name section general operation description...

NAME SECTION

SECTION INDEX

GENERALOPERATION DESCRIPTIONLPG REGULATOR OVERHAULELECTRICAL TROUBLESHOOTINGAPPENDIX

SEC INDEX.fm 1 ページ２００７年２月２２日　木曜日　午後４時５０分

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1.3.0

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1.3.1

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1.3.2

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1.3.3

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1.3.4

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4Y-E LPG Device Repair

Description Page # Date1 Added bookmarks All 3/31/132 Added Information Bulletin page 3-4 3/31/133 Added SIB FS08-001 101 3/31/13

Service Manual Change History

Service Information Buletin1 SIB CC08-005 4Y ECS Controller Programming Change Chapter 192 SIB CE07-008 Error Code AD-1 and AD-7 Chapter 193 SIB CE09-004 A5, A5-1 or 1-1 Error Codes For OPSS Chapter 194 SIB CE10-003 Horn Relocation Chapter E25 SIB CE10-005 Main Wiring Harness Change (Error Code 73-1) Chapter 196 SIB CE11-001R Clamp Release Interlock (Mini Lever Units) Chapter 19, 14, E37 SIB CE11-003 Clamp Release Interlock (Standard Lever Units) Chapter 14, E38 SIB EN07-001 4Y Engine Ignition Timing Procedure Chapter 1.3-109 SIB EN08-001 Repair Manual (00700-X8880-71) Revision Embedded

10 SIB EN08-002 Repair Manual (00700-X8880-71) Revision Embedded11 SIB EN09-001 Repair Manual (00700-X8880-71) Revision Embedded12 SIB EN09-002 Repair Manual (00700-X8880-71) Revision Embedded13 SIB EN10-001 Engine Block Heaters Chapter 1.2-414 SIB FS08-001 LPG Regulator Chapter 1.3-215 SIB HS07-003 Flow Regulator Replacement Parts Chapter 1416 SIB MA07-001 Hourmeter Fuse Installation Chapter 017 SIB MA07-003 Transmission Oil Level Inspection Chapter 2 & 2.118 SIB MA07-004R Grease Specifications Chapter 019 SIB MA10-001 Overhead Guard Mounting Bolt Torque Chapter 920 SIB MA10-007 Oil Pressure Switch Chpater 0 & E321 SIB MA11-001 Service Hint For Greasing Rear Axle Beam Pivot Pin Chapter 022 SIB MA13-001 Exhaust Mounting Clamp with Rubber Bushing Inspection Chapter 023 SIB RA08-001 Updated Horn Pad Chapter 724 SIB ST07-001 Special Service Tools Chapter 1725 SIB TR07-001 Transmission Control Valve Identification Chapter 2 & 2.126 SIB TR07-002 Propeller Shaft Cover Chapter 2 & 2.1

Technical News Brief1 TNB 2007-03R1 Hydraulic Oil Change2 TNB 2007-05 Transmission Knocking Noise At Idle3 TNB 2007-06 LPG Regualtor Slow Path Tamper Resistant Cap4 TNB 2007-11 Torque Specificaion Of Outer Mast Support Bolts5 TNB 2008-07 Fuel Mixture Adjustment Procedure For The 4Y ECS Engine6 TNB 2008-20 Gasoline Fuel System7 TNB 2008-12 Installation of Fuel Line Fittings8 TNB 2009-03 Suppliment to TNB 2008-07 For Adjusting VF (Voltage Fuel)

Hotline Tech Tips1 HTT 2007-022 HTT 2007-033 HTT 2007-044 HTT 2007-055 HTT 2007-066 HTT 2007-077 HTT 2007-088 HTT 2007-099 HTT 2007-10

10 HTT 2007-11

Transmission Control Valve Identification; Proper Chasis LubricationIdle Surge/Hunt; Quick Facts; Rotten Egg/Ammonia SmellLimiting Travel Speed; A5-1 CodeLPG Regulator Adjustment; Engine/Transmission "Knocking" ComplaintTroubleshooting Diesel Smoke; Multifunction DisplayLPG Regulator MaintenanceEngine SurgePropshaft CoverError Code 68-3; Flow Regulator Valve Parts ReplacementWet Brake Option Hydraulic Oil; Error Code AD-1 And AD-7

11 HTT 2007-1212 HTT 2008-0113 HTT 2008-0214 HTT 2008-0315 HTT 2008-0416 HTT 2008-0517 HTT 2008-0618 HTT 2008-0719 HTT 2008-0820 HTT 2008-0921 HTT 2008-1022 HTT 2008-1123 HTT 2008-1224 HTT 2009-0125 HTT 2009-0326 HTT 2009-0627 HTT 2009-0728 HTT 2009-0829 HTT 2009-0930 HTT 2009-1031 HTT 2009-1132 HTT 2010-0133 HTT 2010-0234 HTT 2010-0335 HTT 2010-0436 HTT 2010-0537 HTT 2010-0638 HTT 2010-0739 HTT 2010-0840 HTT 2010-0941 HTT 2010-1042 HTT 2010-1143 HTT 2010-1244 HTT 2011-0145 HTT 2011-0246 HTT 2011-0347 HTT 2011-0448 HTT 2011-0549 HTT 2011-0650 HTT 2011-0751 HTT 2011-0852 HTT 2011-0953 HTT 2011-1054 HTT 2011-1155 HTT 2011-1256 HTT 2012-01

Engine Analyzer Screen 10/10Error Code 09-1; LPG Filter Kit; Cold Soak Lack Of Travel

Engine Analyzer Screen 4/10Engine Analyzer Screen 5/10Engine Analyzer Screen 6/10Engine Analyzer Screen 7/10Engine Analyzer Screen 8/10Engine Analyzer Screen 9/10

Engine Analyzer Screen 3/10

SAS Manual Lowering Valve Location; Flow Regulator W/ Part NumbersSAS Code History Check Without The AnalyzerClearing 01-1, 01-2, 01-3, 01-4, 01-5, 01-6 Codes After Making The Repair Error Code 73-1 After Replacing The Main HarnessHour Meter Diagnostics & MemoryDiagnosing Diesel SmokeLPG Regulator Adjustment & Tar Draining: Idle Speed AdjustmentHow To Read An O2 SensorRequired Adjustments For New LP Regulator, And Installation Of Anti-Tamper CapsEngine Analyzer Screen 1/10; Throttle Body CleaningEngine Analyzer Screen 2/10; Analyzer Speed Versus Displayed Speed

Error Code AD-7 After Replacing The Main Harness

Load Sensor Wire Breakage; Dual Brake Pedal "Low Pedal" ComplaintError Code OB-1 Horn Pad Improvements; Flow Regulator Update; Overheat DiagnosticsEngine Controller Version IdentificationIdentifying LPG Regulator 1st Valve Material; High Engine Idle IssuesUsing the Engine Analyzer To Check The Engine FunctionError Codes Without An Hour Meter Reading; LPG Filter Kit PNReverse Polarity Damage IssuesIgnition Timing Value (IGT) Shown On AnalyzerError Code 06-3; Error Code 01-5To Throttle Valve Actuation And Error Code 06-3 E-THRO Fuse Location

Error Code 73-1, Or Missing Plug On New Harness

Error Code List; Rear Pillar Assist Relay Location; New CabCarriage Roller ReplacementFuel Shut Off Valve Orientation On Gasoline And Dual Fuel TrucksDriveability Issues Due To Dirty Throttle BodyShift Interlock (Intelli-Shift) Adjustments; Overheat Trouble ShootingLPG Tamper Resistant CapCam Positions SensorSAS Matching; Transmission RepairSeatbelt Interlock; Function Menu w/ Travel & Load Handling Option; Gas Tank PressureAccelerator Sensor Codes; LPG Filter Kit Service PartsCNG Trucks Using The Analyzer; Extra Long Feeler Gauges for Mast Shimming Checks

"L-OFF" ComplaintHorn Pad Improvements; Correct Timing Mark On Crank Pulley

…..This Page Intentionally Left Blank…..

0-1

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GENERALPage

TYPE OF LPG DEVICES........................................0-2ENGINE PERFORMANCE CURVES .....................0-3ENGINE SPECIFICATIONS ...................................0-6PRINCIPAL DIFFERENCES FROM GASOLINE VEHICLE ...............................0-7

ABBREVIATIONS...................................................0-7GENERAL RULES OF SERVICING WORK ..........0-8BOLT & NUT TIGHTENING TORQUES.................0-9

BOLT STRENGTH CLASS IDENTIFICATION METHOD AND TIGHTENING TORQUE ....................0-9

PRECOATED BOLTS(BOLTS WITH SEAL LOCK AGENT COATING ON THREADS) ..................................0-12

PERIODIC MAINTENANCE .................................0-13INSPECTION METHOD ..........................................0-13PERIODIC REPLACEMENT PARTS.........................0-13

00.book 1 ページ２００７年２月２２日　木曜日　午後４時４５分

LPG Device for 4Y-E Engine

Section 1.3.0

0-20-2

TYPE OF LPG DEVICES1. Types of LPG cylinders

2. Types of LPG cylinder brackets

Gas weight Cylinder length Specification Pneumatic models

Cushion models

15 kg (33.1 lb) 637 mm (25.1 in)General purpose — STDWith level gauge and quick coupling — OPT

20 kg (44.1 lb) 797 mm (31.4 in)General purpose STD —With level gauge and quick coupling OPT —

CylinderRemoval/installation method Bracket opening direction Fuel hose connecting

positionWeight External diameter

20.0 kg (44.1 lb)

797 mm (31.4 in)

Sinple type (STD)Swing down type (OPT) Right Bottom

15.0 kg (33.1 lb)

637 mm (25.1 in) � � �



Section 1.3.0

0-3

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ENGINE PERFORMANCE CURVES4Y Engine (8FGU15 to 25, 8FGCU20 to 32)

Gasoline (Exclusive, Convertible)LPG (Exclusive, Convertible)

Engine speed

Fuel

con

sum

ptio

n ra

tioSh

aft o

utpu

tSh

aft t

orqu

e



Section 1.3.0

0-40-4

4Y Engine (8FGU30, 32)

Gasoline (Exclusive)

Gasoline (Convertible with LPG)

Engine speed

Fuel

con

sum

ptio

n ra

tioSh

aft o

utpu

tSh

aft t

orqu

e

LPG (Exclusive, Convertible)




Section 1.3.0

0-5

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4Y Engine (8FGU15 to 32 series, 8FGCU15, 18 and 8FGCSU20)


Engine speed

Fuel

con

sum

ptio

n ra

tioSh

aft o

utpu

tSh

aft t

orqu

e



Section 1.3.0

0-60-6

ENGINE SPECIFICATIONS

A: Gasoline (Exclusive)B: Gasoline (Convertible)C: LPG (Exclusive, Convertible)

4Y8FGU15 to 25

8FGCU20 to 32 8FGU30, 32 8FGCU15, 18 and 8FGCSU20

A B C A B C A B C

Maximum shaft torque

N·m (kgf·m)

160 (16.3) � �

165 (16.8)

162 (16.5)

160 (16.3)

160 (16.3) � �

rpm 2100 � � 2570 � 2200 2100 � �

Maximum shaft output

kW (PS)

38 (51) � �

44 (59)

43 (58)

42 (57)

36 (48) � �

rpm 2570 � � 2570 � � 2250 � �

Minimum fuel consumption ratio

g/kW·h (g/PS·h)

298 (219) �

233 (171)

233 (171) �

310 (228)

298 (219) � �

rpm 2000 � � 2000 � 1600 2000 � �

Idle speed rpm 750 � � 750 � � 750 � �

No-load maximum governed speed

rpm 2570 � � 2570 � � 2250 � �



Section 1.3.0

0-7

PRINCIPAL DIFFERENCES FROM GASOLINE VEHICLE

ABBREVIATIONS

LPGGasoline vehicle

Exclusive vehicle Convertible vehicle

Fuel tank LPG cylinder Gasoline tank and LPG cylinder Gasoline tank

Adapter For LPG For LPG Not providedRegulator For LPG For LPG Not ProvidedFuel pump Not provided For gasoline For gasolineFuel filter For LPG For gasoline, For LPG For gasolineSolenoid valve For LPG For LPG Not provided

Abbreviation (code) Meaning Abbreviation (code) Meaning

ASSY Assembly O/S Oversize

ABDC After bottom dead center OPT Option

ATDC After top dead center RH Right hand

BBDC Before bottom dead center rpm Revolution per minute

BTDC Before top dead center SST Special service tool

BDC Bottom dead center STD Standard

EX Exhaust SUB-ASSY Sub-assembly

IN Intake T = Tightening torque

LH Left hand U/S Undersize



Section 1.3.0

0-80-8

GENERAL RULES OF SERVICING WORK1. Preparation before disassembly

• Prepare necessary mechanic tools, measuring instruments and SST before starting operation.

• When disassembling a complicated assembly, put punch or matching marks at places not affecting thefunction to facilitate reassembly operation. When repairing an electrical system, start operation afterdisconnecting the cable from the battery negative terminal.

2. Inspection during disassembly

• Each time a part is removed, check the part installed state, deformation, damage, roughening state andscratching.

3. Orderly arrangement of disassembled parts

• Disassembled parts shall be arranged orderly. Distinguish the parts to be replaced from the parts to be reused.

4. Cleaning of disassembled parts

• Parts to be reused shall be cleaned and washed thoroughly.

5. Inspection and measurement

• Detailed inspection and measurement shall be carried out as required for parts to be reused.

6. Installation

• Install good parts according to the correct procedure and observing the determined standards (tighteningtorques, adjustment values, etc.).

• Be sure to use genuine parts for replacement of existing parts.

• Be sure to use new packings, gaskets and cotter pins because they are non-reusable parts.

• Coat seal packing on gaskets depending on the places, coat oil on the sliding contact places, coat oil orgrease at specified places, and coat MP grease on oil seal lips before reassembly.

7. Adjustment and operation check

• Adjust to the service standard values by using gages, a multimeter, etc.



Section 1.3.0

0-9

BOLT & NUT TIGHTENING TORQUESStandard Bolt & Nut Tightening TorqueTightening torques of standard bolts and nuts are not indicated throughout the manual.Use the procedures and table below to judge the standard tightening torque.

1. Judge the tightening torque for the hexagon head bolt, welded bolt or stud bolt having the standard bearingsurface according to the tightening torque table by identifying the bolt strength class from the table below.

2. Judge the tightening torque for the hexagon flange bolt based on the threading diameter.

3. The nut tightening torque can be judged from its corresponding bolt type by using procedure 1.

BOLT STRENGTH CLASS IDENTIFICATION METHOD AND TIGHTENING TORQUE

Identification by Actual Part

Type Shape and Strength class Strength class

Hexagon head bolt (standard bearing

surface)

4 = 4T5 = 5T6 = 6T7 = 7T8 = 8T

4T

5T

7T

8T

Welded bolt 4T

Stud bolt

4T

6T

Number in relief or hallmark on head

No mark

Bolt with two raised lines on head

Bolt with three raised lines on head

Bolt with four raised lines on head

No mark

About 2 mm (0.08 in.) groove(s) on one/both edge(s)



Section 1.3.0

0-100-10

Identification by Part No.

Tightening Torque Table

Type Part No. Shape

Hexagon bolt

Stud bolt

Strength class Nominal diametermm

Pitchmm

Standard tightening torque

N·m kgf·cm ft·lbf

4T

68

10121416

1.01.251.251.251.51.5

5.413254775113

551302604807601150

4.09.4

18.834.754.983.0

5T

68

10121416

1.01.251.251.251.51.5

6.516325991

137

65160330600930

1400

4.711.623.843.367.1

101.1

6T

68

10121416

1.01.251.251.251.51.5

7.8193972

108172

8019540073011001750

5.814.128.952.779.4

126.6

7T

68

10121416

1.01.251.251.251.51.5

11255295

147226

110260530970

15002300

7.918.838.370.0

108.3166.1

8T

68

10121416

1.01.251.251.251.51.5

122961

108172265

125300620110017502700

9.021.744.979.4

126.6195.3

91611-40625Nominal length (mm)Nominal diameter (mm)Strength class

Nominal diameter

Nominal length

92132-40614Nominal length (mm) Nominal diameter (mm)Strength class

Nominal diameter

Length



Section 1.3.0

0-11

Identification by Bolt Shape (Hexagon flange bolt)

Tightening Torque Table (Hexagon flange bolt)

Class 4.8T 6.8T 8.8T 10.9T 11.9T

Hexagon flange bolt

- -

Strength class Nominal diametermm

Pitchmm

Standard tightening torque

N·m kgf·cm ft·lbf

4.8T

68

10121416

1.01.251.251.251.51.5

5.513275078

120

56130280510800

1220

49

20375888

6.8T

68

10121416

1.01.251.251.251.51.5

7.5193971110170

8019040072011201730

614295281125

8.8T

68

10121416

1.01.251.251.251.51.5

122961110175270

120300620112017802750

9224581129199

10.9T

68

10121416

1.01.251.251.251.51.5

15.53880

145230360

160390820

148023503670

122859107170266

11.9T

68

10121416

1.01.251.251.251.51.5

17.54289

160260400

180430910

163026504080

133166118192295

No mark

No mark



Section 1.3.0

0-120-12

PRECOATED BOLTS(BOLTS WITH SEAL LOCK AGENT COATING ON THREADS)

1. Do not use the precoat bolt as it is in either of the followingcases:

(1) After it has been removed.

(2) When it has been moved by tightness check, etc.(loosened or tightened)

Note:For torque check, tighten the bolt at the lower limit of theallowable tightening torque range; if the bolt moves, retightenit according to the steps below.

2. How to reuse precoated bolts

(1) Wash the bolt and threaded hole.(The threaded hole must be washed even when replacingthe bolt with a new one.)

(2) Completely dry the washed parts by blowing with air.

(3) Apply the specified seal lock agent to the bolt threadedportion.

Seal lock agent



Section 1.3.0

0-13

PERIODIC MAINTENANCE

INSPECTION METHODI: Inspection. Repair or replacement if required.C: Cleaning *1: Soapy water *2: Detector

PERIODIC REPLACEMENT PARTS

Inspection Period Months 1 3 6 12Item Hours 170 500 1000 2000Gas leak from piping and joint I*1

� � � �

Damage of piping and joint I*2� � � �

Tar removal from regulator C � � � �

Regulator adjustment status I � � � �

Regulator function I � � �

Adapter I � � �

Filter clogging C � � �

Loosened installation and functioning of solenoid valve I � � �

Gas cylinder I � � � �

Looseness and damage of gas cylinder mounting I � � � �

Item Replacement timingO-ring for LPG cylinder valve Every 24 monthsLPG high and low-pressure rubber hoses Every 24 monthsLPG regulator diaphragm and O-ring Every 36 months or 2500 hoursFuel filter Every 36 months or 2500 hours



Section 1.3.0

1-1

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OPERATION DESCRIPTIONPage

OUTLINE OF LPG DEVICE....................................1-2FUEL FILTER FOR LPG ........................................1-3SOLENOID VALVE.................................................1-3ADAPTER...............................................................1-4REGULATOR..........................................................1-5

SPECIFICATIONS ....................................................1-5REGULATORS SYSTEM COMPONENTS .................1-11

01.book 1 ページ２００７年２月２２日　木曜日　午後４時４６分


Section 1.3.1

1-21-2

OUTLINE OF LPG DEVICELPG (in liquid form supplied from the cylinder) passes through the LPG filter in the engine room to remove foreignmatter and reaches to the regulator through the main solenoid valve. LPG is reduced and gasified in the regulator,and supplied to engine with its pressure kept at a certain rate.Engine coolant is led to the regulator for use as the heat source for LPG gasification.

BatteryIgnitionswitch Fuse

LPGfilter

Main solenoid

valve

Valve

LPG

Cylinder

Regulator set

Regulator

Injector path

Main path

Coolant path

Slow solenoid valve

Engine

AdapterInjector



Section 1.3.1

1-3

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FUEL FILTER FOR LPGThe filter is mounted between the LPG cylinder and the right beforethe solenoid valve to remove various kinds of foreign materials inLPG. It consists of a filter element and permanent magnet, and thefilter element is detachable for easy cleaning and has sufficientlystrong construction to withstand LPG vapor pressure.When low-grade LPG is used, vary small impurity particles flow intothe regulator causing start difficulty due to clogging of the slowpath. The filtering performance has been improved to be able toremove foreign matters of 2 �m or more in size.

SOLENOID VALVEThe solenoid valve is mounted between the LPG filter and theregulator, and controls gas flow according to the engine condition.For example, when the engine is running, the solenoid valve is ONand supplies fuel. Once the engine stops running, it turns OFF andcuts off the gas flow.When the current flows through the solenoid valve, which consistsof a slide valve, back spring, and solenoid coil, magnetic force isgenerated. The slide valve overcomes the spring force by suchmagnetic force to move forward the IN side, and fuel flows.When the current stop flowing through the solenoid valve, the slidevalve is forced to back to the OUT side by the LPG pressure andspring force to shut off the flow.

From LPG cylinder

To Main solenoid valve

Filter element

Filtering Performance 2 �m

To Regulator

From LPG filter

IN

Back spring

OUT

Solenoid coil



Section 1.3.1

1-41-4

ADAPTERThe adapter is installed on the right upper position of the electricgovernor, and mixes air with gaseous LPG decompressed in theregulator. The air-mixed fuel is led to the engine. The adapter has aFCM (Fuel/air Control Motor) at the ventury part and the FCMcontrols the amount of fuel based on the engine ECU signal. Themotor has a taper-shaped needle valve that moves right or leftbased on the engine ECU signal. This sliding of the valve changesthe opening space of the fuel path.

Specifications

FCM specifications

Seatdiameter

Needle valve

Ventury

FCM

Electronic governor

Venturydiameter

Seatangle

Ventury diameter mm (in) 24 (0.9)Needle valve seat diameter mm (in) 11 (0.4)Needle valve seat angle � 60

Magnetized way 1-2 magnetized typeStroke mm (in) 5 (0.2)

[0.05 (0.002) / step]Pulse generation rate pulse / second 140



Section 1.3.1

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REGULATORThe regulator supplies vaporized LPG after pressure reduction to the engine while maintaining the pressure at a fixedlevel.

SPECIFICATIONS

First chamber pressure kPa (psi) 24.5 to 34.3 (3.6 to 5.0)First seat inner diameter mm (in) 3.2 (0.1)Secondary seat inner diameter mm (in) 6.0 (0.2)Slow system flow shut off method Solenoid valveDrain cock Optionally available



Section 1.3.1

1-61-6

Regulator FunctionThe LPG is gasified by depriving the engine coolant, led into the regulator, of heat. The regulator consists of chamberA where LPG vaporization starts, chamber B (first reducing chamber) where the gasified LPG pressure is reduced,chamber C (second reducing chamber) for reducing the pressure down to almost atmospheric level to supply fuelusing the adopter venturi vacuum, and chamber D for forced fuel supply during engine start and idling.

LPG flowing into chamber A of the regulator pushes elastic face valve 1 open by vapor pressure allowing it to enterfirst reducing chamber B where it is vaporized by pressure reduction. When the pressure in chamber B becomes inthe range of 24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) (3.6 to 5.0 psi), first diaphragm pushes first regulator spring, sofirst diaphragm hook acuates first valve lever to close elastic face valve 1. When LPG flows out to second reducingchamber C, the first pressure drops and first valve lever is operated by first regulator spring to open elastic face valve1 to cause fuel to flow into first reducing chamber B again. Opening and closing of elastic face valve is repeated tomaintain the first pressure at a fixed level. The pressure of the fuel entering from chamber B into chamber C throughelastic face valve 2 is reduced to atmospheric level. Chamber C is connected to the adapter.The vacuum of the ventury nozzle at the adapter operates second diaphragm to open elastic face valve 2 via secondvalve lever. The valve is closed by the force of second regulator spring to maintain a constant pressure (atmosphericpressure).

Slow path

Main path (to adaptor)

Elastic face valve 2

Chamber C

Secondary diaphragmSecond valve lever

Injector path(to injector)

Chamber D

Slow solenoid valve

Chamber B

First diaphragm hook

First regulator spring

First diaphragm

First valve lever


Chamber A



Section 1.3.1

1-7

1. When starting the engineWhen the ignition switch and LPG switch are both turned to ON, the LPG led from the IN port flows into chamberA. Upon entering chamber A, the LPG pushes open the elastic face valve 1 by its own vapor pressure, andenters the primary pressure reduction chamber B for pressure reduction and vaporization. When the pressure inchamber B reaches in the range of 24.5 to 34.3 kPa (3.6 to 5.0 psi), first diaphragm pushes first regulator springto operate first valve lever by means of first diaphragm hook. As a result elastic face valve is closed and thepressure in the primary pressure reduction chamber B remains at a constant level. When the starting motor runs,the current flowing in the coil of the slow solenoid operates the valve to connect chambers B and D. Since thepressure in chamber B at 24.5 to 34.3 kPa (3.6 to 5.0 psi) is higher than the atmospheric pressure, LPG flowsinto chamber D. The LPG entering chamber D flows through the slow path, and main path into the adapter, andis then supplied to the engine from the venturi nozzle to start initial explosion. When the throttle valve at theelectric governor is opened slightly then, vacuum is generated in the venturi of the adapter. The vacuum in theadapter acts on the secondary pressure reduction chamber C via the main path. At this time, secondarydiaphragm is operated to open elastic face valve 2 via second valve lever to cause LPG to flow from the primarypressure reduction chamber B to the secondary pressure reduction chamber C.As a result, a large amount of LPG enters the adapter for consecutive combustion.

Slow path

Main path (to adaptor)


Chamber C

Secondary diaphragmSecond valve lever

Injector path(to injector)

Chamber D

Slow solenoid valve

Chamber B

First diaphragm hook

First regulator spring

First diaphragm

First valve lever


Chamber A

IN port



Section 1.3.1

1-81-8

2. During idlingWhen the engine is idling, current flows to the slow solenoid valve coil to operate the valve, resulting in openingof the closed path to connect chambers B with D. Since the pressure in chamber B is high enough, thedepressurized LPG flows chamber D. Though most of the fuel flown to chamber D is led to the adapter throughthe slow path, main path, and venturi nozzle of the adapter, and then supplied to the engine, fuel is alsodelivered to the engine by the LPG injector to compensate the air-fuel ratio. The idle adjusting screw controlsmain flow rate of fuel. Since vacuum at the adapter is very low during idling, elastic face valve 2 is not openedand the fuel is supplied not from the chamber C, but from the slow path.

LPG injector

Injector path

Slow solenoid valve

Chamber D

Chamber B


Idle adjusting screw

Slow pathMain path

Chamber C

Adapter

Ventury nozzle



Section 1.3.1

1-9

3. During normal operationWhen the throttle valve is opened, vacuum arises at the adapter venturi nozzle, which is applied to chamber Cthrough the main path. This vacuum pulls second diaphragm to open elastic face valve 2. As a result, LPG flowsfrom chamber B to chamber C, and enters the adapter venturi nozzle through the main path.As a current also flows in the slow solenoid valve, LPG also flows from chamber B to chamber D, and throughthe slow path to the venturi nozzle, and is also supplied to the engine by the LPG injector through the injectorpath.While the engine is running in medium load range, LPG fuel is mostly supplied through the main path, and LPGinjector injects the shortage amount of fuel to the ideal air-fuel ratio.While the engine is in high load range, the FCM at adapter changes the amount of fuel flow to adjust the overallfuel amount, on the other hand, the injector supplies a fixed amount of fuel with engine.

LPG injector

Injector path

Slow solenoid valve

Chamber D

Chamber B


Slow path

Second diaphragm

Chamber C

Adapter

Main path

Ventury nozzle

Throttlevalve

FCM



Section 1.3.1

1-101-10

4. When stopping the engineWhen the engine stopped, the current to the slow solenoid valve is cut off to close the path between chambers Band D, resulting in suspension of LPG supply through the slow path. Since the vacuum at the adapter venturidoes not exist, LPG supply through the slow path also stops.

LPG injector

Slow solenoid valve

Chamber D

Chamber B

Adapter

Slow path



Section 1.3.1

1-11

REGULATORS SYSTEM COMPONENTS

LPG Cutoff DeviceThe solenoid valve for slow path control is integrated with the regulator. The solenoid valve is opened and closedaccording to the engine speed, starter signal etc. detected by means of engine ECU. When the ignition switch is ON,with the engine not running, the valve is closed not to flow LPG to the adapter.

Ignition switch ST

ONAM

EFImainrelay

Battery

LPGSolenoidrelay

Slowsolenoid

Mainsolenoid

Engine ECU

Gasoline

Starterrelay

Startermotor

Igniter

LPG-Gasoline switch

LPG



Section 1.3.1

2-1

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LPG REGULATOR OVERHAULPage

PRECAUTION FOR LPG FORKLIFT OPERATION AND REPAIR ........................................................2-2

REGULATOR..........................................................2-3REMOVAL·INSTALLATION .....................................2-10DISASSEMBLY·REASSEMBLY ...............................2-12

LPG LEAK INSPECTION.....................................2-17ENGINE ADJUSTMENT.......................................2-18



Section 1.3.2

2-22-2

PRECAUTION FOR LPG FORKLIFT OPERATION AND REPAIRHandle LPG with special attention, because it is inflammable and may cause explosion resulting in the fatal accident.

1. Never smoke tobacco, strike a match and light a lighter near the LPG forklift. Never park and stop the LPGforklift near a stove, gas burner, electric heater, electric apparatus (a motor, etc), bonfire, etc. (near the fire).Avoid the direct sunlight, if possible.

2. Never operate the LPG forklift near the fire.

3. When Operating, inspecting and repairing the LPG forklift, put up “CAUTION INFLAMMABLE” to avoid any fire.

4. When repairing the LPG forklift, remove the engine key so that it cannot be operated by persons other than theoperator.

5. Use a gas leak detector, soapsuds or neutral detergent solution to detect gas leak. Never use other device orliquid, etc.

6. To check gas leak at night, be sure to light a flashlamp outside the chamber before approaching to the LPGforklift (to prevent a hazard by switching spark).

7. When gas should leak, ventilate air after confirming that there is no fire.

8. Pay special attention to keep the LPG cylinder. Keep it in the place free from the fire and install a gas leakdetector.

9. When a LPG forklift is used for a long time, impurities in fuel and tank rust accumulate in its inside. The operationof the LPG devices becomes defective by various causes. In this case, the LPG devices must be inspected,repaired and washed. When disassembling and reassembling the regulator, pay special attention to itsadjustment and airtightness.

10. Be sure to apply liquid packing to the threaded parts of each part (the union, solenoid valve, etc.). Never applyliquid packing to the first and the second threads of the screw tip.



Section 1.3.2

2-3

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REGULATORGeneral



Section 1.3.2

2-42-4

Components

Solenoid valve

First valve ASSY Idle adjust screw

O-ring

First cover

First diaphragm

Second valve ASSY

Second diaphragm

Second cover



Section 1.3.2

sheath

Text Box

Click here for information on LP regulator kits

2-5

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SSTs for LPG Regulator Overhaul

No. Part No. Part Name1 09813-26600-71 Gauge2 09814-22000-71 Tool3 09815-22000-71 Tool4 80339-76026-71 Automatic choke pipe plug5 09817-23600-71 Union6 09819-23600-71 Gauge7 09819-22000-71 Gauge8 23627-22000-71 Spring9

9-19-29-3

09820-23600-7109823-23600-7109822-22000-7109821-22000-71

Tester SUB-ASSYUnionGaugeBellows

1

2

3

4

5

6

7

8

9-3

9-

9-1

9-2



Section 1.3.2

2-62-6

How to Deal with Tamper Proof Ring

GeneralIt is not basically necessary to adjust VF voltage and regulatorprimary pressure, but at regulator overhauling, remove the tamperproof rings to adjust them. Follow the procedure described below totreat the tamper proof rings.

Disassembly:

1. Cut off the head of the tamper proof ring using a hacksawshown in the illustration.

2. Remove the idle adjusting screw and/or regulator primarypressure adjust screw.

3. Using a pair of nippers, remove the ring.

Reassembly:

1. Install the idle adjusting screw temporarily.

(1) Set the mixture adjust screw temporarily to the followingdimension:Temporal set value: 6.2 mm (0.25 in)

(2) Make sure to install a new cap (21673-13370-71) afterthis adjustment is made on the vehicle.

Make sure to adjust the engine speed after installing theregulator on the vehicle.

2. Install the regulator primary pressure adjusting screw.

(1) Install the screw and nut.

(2) Using SST, adjust the protrusion of the screw.

SST 09819-22000-71

3. Install the tamper proof ring (21673-13370-71).


6.2

mm

(0.2

5 in

)

SST



Section 1.3.2

2-7

Troubleshooting

Inspection 1

1. Remove the idle adjusting screw and install the SST.

SST (Union) tightening torque:T=0.2 to 0.3 N·m (2 to 3 kgf·cm) [0.14 to 0.19 ft·lbf]

2. Supply compressed air at 400 kPa (4 kgf/cm2) [57psi] through the IN port and maintain the airpressure.

Note:Don't apply compressed air more than 780 kPa (8kgf/cm2) [110 psi].

3. Check that the SST gauge indicates 0.

SST

SST

Compressed air

SST

Inspection 2

1. Put the SST to the injector port to prevent air fromblowing.

2. Apply 12 V to the slow solenoid valve.

3. See that the SST gauge indicates 24.5 to 34.3 kPa(0.25 to 0.35 kgf/cm2) [3.6 to 5.0 psi].

SST

SST

Compressed air 12 V

SST

Inspection 3

1. Stop supllying the compressed air in state ofInspection 2.

2. Read the SST gauge.SST

SST

12 V

SST

24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) [3.6 to 5.0 psi].

Other than 24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) [3.6 to 5.0 psi].

• In appropriate adjustment of first pressure• Elastic face valve 1 defect • Elastic face valve 2 defect • First diaphragm defect• Clogging of slow path

OK The pointer stays at the same position as that of inspection 2.

The pointer gradually moves toward the 0 position.

To flow (1)

OK

0 NG More than 0

Slow solenoid valve defect

NG

NG

OK

NG

Slow solenoid valve defect

0



Section 1.3.2

2-82-8

Inspection 4

1. Stop supplying the compressed air in the state ofInspection 2.

2. Breathe air into the inner vent port and read theSST gauge.

Air

Inspection 5Apply soapy water on portions A to F of the regulator tocheck any air leakage in state of Inspection 2.

Compressed air

A

F

E

D

C

B

The pointer moves to 0 position. The pointer stays at the position.

• Second diaphragm defect• Elastic face valve 2 (in C chamber) defect.

Leak from A or F. Leak from A, C, D, or E.

Re-check after retightening each part. (Since the fitting at A is applied with a sealing agent, reassemble it.)

From Inspection 3

NGOK

Normal

OK

NG

Flow (1) (from inspection 3)

Leak from B:Defect of idle adjusting screw O-ring.

Leak from F:Body defect.

Result1

Result2

OK NG

• Elastic face valve 2 contact defect

• First diaphragm defect• Loosen of elastic face valve

2 mounting screw

To Inspection 3

No leak from any portion

Leak from D



Section 1.3.2

2-9

Individual Inspection1. Inspect the slow solenoid.

Check that the operating sound is heard when applying 12 V tothe slow solenoid.

2. Inspect the main solenoid.Check that the operating sound is heard when applying 12 V tothe main solenoid.

12 V

12 V



Section 1.3.2

2-102-10

REMOVAL·INSTALLATIONCaution:

• Perform working at a well-ventilated job site and never put fire sources around the vehicle.• Perfectly discharge LPG from the piping before starting removal.• Disconnect the battery negative terminal before handling the fuel system.• After installation, using soapy water, check no LPG leak from any part of each piping before starting the

engine.• After installation, adjust the idling speed. (See page 2-17)

Removal Procedure1 Fully discharge LPG from the fuel piping. [Point 1]

2 Disconnect the battery cable from the negative terminal.

3 Drain engine coolant.

4 Disconnect the wiring from the main and slow solenoid valves.

5 Disconnect the fuel piping.

6 Disconnect the coolant piping.

7 Remove the filter and main solenoid.

8 Remove the regulator ASSY.

Installation ProcedureThe install procedure is the reverse of the removal procedure.

Note:After installation, adjust the idling speed. (See page 2-17)



Section 1.3.2

2-11

Point Operations[Point 1]

Removal:Discharge LPG from the piping according to the procedurebelow.

(1) Close the LPG supply piping valve 1 (green).

(2) Close the LPG outlet valve 2 (amber).

(3) Start the engine, and run the engine in the idling state untilit stops naturally.

1

2



Section 1.3.2

2-122-12

DISASSEMBLY·REASSEMBLYCaution:Perform working at a well-ventilated job site and never put fire sources around the vehicle.

Note:• Wash the outer surface of the regulator and keep the work bench clean.• First, perform individual check of the filter for clogging and the solenoid valve for any abnormality, and

then disassemble the regulator only when its internal abnormality is found by the inspection accordingto the troubleshooting given in this manual.

• Disassemble the regulator carefully, or defects such as diaphragm or valve contacts may occur.T = N·m (kgf·cm) [ft·lbf]

Disassembly Procedure1 Remove the regulator second cover and diaphragm. [Point 1]

2 Remove the second valve ASSY. [Point 2]

3 Remove the first cover, first diaphragm and spring. [Point 3]

4 Remove the first valve ASSY. [Point 4]

5 Remove the slow solenoid valve.

6 Remove the idle adjust screw and O-ring. [Point 5]

Reassembly ProcedureThe install procedure is the reverse of the removal procedure.

1

2

3

5

4

6



Section 1.3.2

2-13

[Point 1]

Reassembly:

1. Install the diaphragm by matching its pin with the concaveportion of the second valve lever.

2. Tighten the screws in the illustrated order.Tightening torque:T = 3.5 to 4.4 N·m (36 to 45 kgf·cm) [2.6 to 3.5 ft·lbf]

[Point 2]

Reassembly:Install the spring by holding it manually so as not to be freedfrom the convex portion of the lever.Carefully perform the work to prevent the lever seat portionfrom being pressed against the housing.

Reassembly:Follow the steps below when the second valve ASSY isreplaced with a new one:

(1) Insert the seat.

(2) Install the spring washer.

(3) Install the snap ring.

(4) Perform valve airtightness test in the state of step 3above. (See page 2-13)

(5) Apply adhesive agent (Castle Super Cement) on the snapring and spring washer. Do not let the adhesive agentadhere on the valve seat portion.

Inspection:Inspect the second valve lever height.Check contact with the lever when passing through the A sideof the SST, and no contact when passing through the B side.

SST 09819-23600-71

Pin Concave portion

1

4

3

2

Convex portion

Spring

Seat portion

Seat

Spring washerSnap ring

SSTB

A



Section 1.3.2

2-142-14

If not satisfied, use the SST to bend the lever for adjustment.

SST 09814-22000-71................................. (1)09815-22000-71................................. (2)

During lever height adjustment, do not push the valve seatagainst the port.

[Point 3]

Disassembly:Since the spring force is applied at each portion, do not tryquick removal but loosen each bolt equally for removal.

Reassembly:Tighten each bolt equally step by step so as not to let springsbe fallen. Tighten in the illustrated order for final tightening.

Tightening torque:T = 3.5 to 4.4 N·m (36 to 45 kgf·cm) [2.6 to 3.5 ft·lbf]

Disassembly:Since the diaphragm hook is engaged with the first valve lever,move the diaphragm in the direction of the arrow in theillustration for removal.

Reassembly:Engage the diaphragm hook onto the first valve lever tip.

[Point 4]

Disassembly:

1. Remove the first valve ASSY.

2. Disassemble the first valve.

Reassembly:

1. Reassemble the first valve ASSY.

Note:Replace the O-ring with a new one.

2. Install the first valve sub-assembly.

Tightening torque:T = 3.5 to 4.4 N·m (36 to 45 kgf·cm) [2.6 to 3.3 ft·lbf]

SST (1)

SST (2)

81

3

2

46

79

5

Diaphragm hook

First valve lever

O-ring



Section 1.3.2

2-15

3. Check the first valve air-tightness.

(1) Put the SST (spring) between the lever tip and regulatorbody.

SST 23627-22000-71

(2) Connect the SST (gauge) to the fuel inlet.

SST 09820-23600-71

(3) Check that the air does not leak from the valve until airpressure become in the range of 49.0 to 58.8 kPa (0.5 to0.6 kg/cm2) [2.7 to 7.0 psi]. If air leaks before the airpressure reaches at the range, replace the elastic facevalve 1.

4. Check and adjust the first lever height.

(1) Push the first valve at the elastic face valve side.

(2) Check contact with the lever when passing through the Sside of the SST, and no contact when passing through theT side.

SST 09813-26600-71

Reference height:11.8 to 12.3 mm (0.47 to 0.48 in) from the regulator contactsurface.

5. Using SSTs, adjust the first valve lever height if it is not withinthe specified range.

SST 09814-22000-71................................. (1)09815-22000-71................................. (2)

Note:• Do not apply force to the valve seat, or the valve seat will

be damaged.• Be sure to set the SST with a cut on the valve lever.

6. Hang the diaphragm hook at the tip of the first valve lever andset the diaphragm to the regulator body.

7. Install the regulator first cover to the body, with pushing thediaphragm spring manually.

Tightening torque:T = 3.5 to 4.4 N·m (36 o 45 kgf·cm) [2.6 to 3.3 ft·lbf]

SST

SST

SST

T

S

SST (1)

SST (2)



Section 1.3.2

2-162-16

8. Adjust the first diaphragm adjust screw.

(1) Loosen the adjust screw nut.

(2) Using SST, adjust the protrusion of the screw.

SST 09819-22000-71

Reference height: 13.9 mm (0.5 in)

9. Adjust the pressure of first reducing chamber. (See page 2-17)

[Point 5]

Reassembly:Temporarily adjust the idle adjusting screw.After tightening until the tip end of the adjusting screw comeinto contact with the body loosen the screw by 3 turns.

Note:• Do not tighten the adjusting screw too hard.• After installing the regulator on the vehicle, be sure to

adjust the VF voltage. (See page 2-18)

Second Valve Airtightness Check1. Temporarily install the second valve ASSY.

2. Remove the idle adjusting screw and install the SSTs.

SST (union) tightening torque:T = 0.2 to 0.3 N·m (2 to 3 kgf·cm) [0.14 to 0.19 ft·lbf]

SST 09817-23600-71................................. (1)09820-23600-71................................. (2)

3. Put the SST to the injector port.

SST 80339-76026-71................................. (3)

4. Apply 12 V to the slow solenoid valve.

5. Inject compressed air through the SSTs and make adjustmentof the seat position to ensure no air leakage by tilting the valve,as shown in the illustration.

SST


SST (2)

SST (1)

SST (3)



Section 1.3.2

2-17

LPG LEAK INSPECTIONCaution:

• After repairing each part of the LPG system, use soapy water to check no LPG leakage from any partbefore starting the engine.

• Never use fire for inspecting gas leakage.• Never use a match or lighter for illumination at the time of inspection at night.

1. Open the valve between the LPG cylinder and hose. (The LPG is led to the regulator by this operation.)

2. Remove the idle adjust screw and install the SST.SST 09817-23600-71

3. Apply 12 V to the main and slow solenoid valves.

4. Using soapy water or aqueous solution of a neutral detergent, check no gas leakage from each joint (illustratedbelow).

5. Be sure to wipe the liquid off after the leak check.



Section 1.3.2

2-182-18

ENGINE ADJUSTMENTNote:To measure values described below, use the multifunctiondisplay or plug-in analyzer.

1. Warm up the engine until the coolant temperature be 80�C(176�F) or higher.

2. Check the engine idle speed.

Standard: 750 ± 150 rpm

3. Check the initial advanced ignition timing.

(1) Using SST, connect the terminal TC and E1 of thediagnosis connector.

SST 09238-13130-71

Notice:Be sure to connect the correct terminals.If connecting wrong terminals, malfunction may occur.

(2) Using a timing light, check the ignition timing.

Standard: 7� BTDC/750 rpm

4. Adjust the initial advaced ignition timing.

(1) If the ignition timing is not as specified above, loosen thetwo distributor clamp bolts and turn the distributor foradjustment.When delayed: Turn counterclockwise.When advanced: Turn clockwise.

(2) After adjustment, tighten the bolts and check the ignitiontiming again.

5. Check LPG regurator primary pressure

(1) Install the SST to the LPG regulator.

SST 09817-23600-71................................. (1)09820-23600-71................................. (2)

(2) Start the engine.

(3) Check the LPG regulator primary pressure.

Standard: 24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) [3.6 to 5.0 psi]

Note: The pressure remains as above one.

SST (2)

SST (1)



Section 1.3.2

2-19

6. Adjust LPG regurator primary pressure


(2) Loosen the adjust screw nut and adjust the primarypressure by turning the screw.

Standard: 24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) [3.5 to 5.0 psi]

7. Check and adjust VF voltage

(1) Warm up the heated oxygen sensor by maintaining theengine speed at 1800 rpm for approximately 2 minutes.

(2) Check the oxygen sensor feedback signal (OX) valuechanges alternately between 0 and 1.

Standard: The feedback signal (OX) value changes alternately morethan 4 times for 20 seconds.

Note: Maintain the engine rpm at 1800 rpm.

(3) Measure the VF voltage while engine idling.

Standard: 2.5 ± 0.5 V

(4) If the standard condition is not satisfied adjust the VFvoltage into the specified range by turning the idle adjustscrew of the regulator slowly.

Reference:

(5) After racing the engine several times, check that the VFvoltage is within the specified range.

Note:• Adjust the VF voltage to the 2.5 V as possible.• If VF voltage is 2.5 V, but OX signal value is not changed

alternately, disconnect and reconnect the battery negativecable, and perform this step (7) again.

CLOCKWISECOUNTERCLOCKWISEVF

voltage Condition Measures

0 V Air fuel ratio:RICH

Turn the screw CLOCKWISE

5 V Air fuel ratio: LEAN

Turn the screw COUNTERCLOCKWISE



Section 1.3.2

3-1

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ELECTRICAL TROUBLESHOOTINGPage

BEFORE TROUBLESHOOTING............................3-2CONNECTOR HANDLING.........................................3-2WIRE HARNESS AND CONNECTOR INSPECTION

PROCEDURE ........................................................3-2BEFORE BEGINNING TROUBLESHOOTING ......3-4DIAGNOSIS (SELF DIAGNOSIS FUNCTION).......3-5

GENERAL...............................................................3-5HOW TO INTERPRET THE FLOW-CHARTS ........3-6ANALYZER.............................................................3-7

EXPLANATION........................................................3-7ANALYZER MENU SCREEN LIST..............................3-8

ABOUT TROUBLE SHOOTING BY ERROR CODES .............................................3-9TABLE OF DIAGNOSIS CODES ..............................3-10

TROUBLESHOOTING BY SYMPTOMS ..............3-12PARTS INSPECTION AND ADJUSTMENT.........3-37

03.book 1 ページ２００７年２月２２日　木曜日　午後４時４７分


Section 1.3.3

3-23-2

BEFORE TROUBLESHOOTING

CONNECTOR HANDLING1. Disconnect the battery plug before connecting or

disconnecting each connector or terminal.

2. When unplugging a connector, first remove the lock then,without pulling the harness, pull out the connector whileholding the main unit.To connect, push the connector fully until it is locked inposition.

3. When applying tester probes, always do so from the rear of theconnector (harness side).

4. When this is not possible, such as with waterproof testerprobes, make sure that inserting will not deform the connectorterminal.

5. Do not touch connector terminals directly with your hand.

6. When bringing tester probes into contact with live terminals,prevent two tester probes from coming into contact with eachother.

WIRE HARNESS AND CONNECTOR INSPECTION PROCEDUREWhen any trouble occurs, first inspect the connectors and wireharness of the related circuit according to the following procedure.

Continuity Inspection1. Disconnect connectors at both ends of the relevant harness.

2. Measure the resistance between corresponding terminals ofthe connectors at both ends.

Standard: 10 � or less

Note:Move the wire harness slightly from side to side and up anddown while measuring.

Reference:The cause of disconnections is almost always the connector asdisconnections in the vehicle's central wiring are rare. Inspectespecially the sensor connectors with sufficient care.

Short Circuit Check1. Disconnect connectors at both ends of the relevant harness.

2. Measure the resistance between the corresponding connectorterminal and N1. Always inspect the connectors at both ends.

Standard: 1 M� or above

Note:Move the wire harness slightly from side to side and up anddown while measuring.



Section 1.3.3

3-3

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101112131415161718192021E

3. Measure the resistance between the relative terminals of theappricable connector.

Standard: 1 M� or above

Note:The wiring may short-circuit due to pinching by the body ordefective clamping.

Visual and Contact Pressure Checks1. Disconnect connectors at both ends of the relevant harness.

2. Perform a visual check to make sure that there is no rust orforeign matter contaminating the connector terminal.

3. Check that the caulking is not loose or damaged, and, afterchecking that there is no damage, gently tug the connector orwire harness to make sure that it cannot be pulled out.

4. Insert a male terminal same as that of the terminal to a femaleconnector and check the extracting force.Defective contact may exist at a terminal where the extractingforce is less than that of other terminals.

Note:If a problem, such as rust or foreign matter on the terminal, ora drop in the contact pressure of male/female terminalsoccurs, a solution that often works is simply disconnectingand re-connecting the connected connector to change thecontact conditions. Try disconnecting and re-connectingseveral times. If such a defect is recognized, it is likely thatthere is a defective terminal contact.



Section 1.3.3

3-43-4

BEFORE BEGINNING TROUBLESHOOTINGIt is not appropriate to begin trouble shooting for the 4Y engine on the basis of results only. It can lead to mistakencorrective action, wasted time, and sometimes to an increase in abnormalities. Therefore, please pay carefulattention to the details surrounding the time when a fault occurs, to be supplied by the customer based on thefollowing.

Diagnostic ProcedureFirst, it is necessary to get the "fault history and service history" for the vehicle, and then to gather definiteinformation about the fault occurrence such as "when", "at what times", "in what places", "during what operations oractions", and "what happened afterwards".Also, try to recreate the conditions for the fault occurrence. (a. The fault cannot be recreated, b. The fault can berecreated: Upon doing what?)

General items

Condition of the defect (Tick the items that apply)

Customer name Date of shipment of vehicle Date of fault occurrence / hour meter reading

Vehicle model Frame No. Engine No. (punched)

Fuel used�Gasoline �LPG �Gasoline/LPG combination (Reference LPG fuel company name: )

Defect phenomena1. Cannot start a. Does not crank b. Combustion does not start c. Incomplete combustion2. Does not start well Poor cranking (when cold · when warm · at all times)3. Poor idle a. Poor idle speed b. Unstable idle speed c. Hunting (Regular fluctuation in idle speed)

4. Engine stallinga. Directly after startup (when cold · when warm) b. During reduction of speedc. After reduction of speed d. Without warning e. After engine running roughf. When steering g. During material handling h. Can be re-started immediately

5. Defective operational statusa. Insufficient power output b. Hesitationc. Surging (swaying forward and backward during acceleration)d. Knocking e. Back fire f. After fire

6. Others a. Excessive fuel consumption b. Excessive oil consumption c. Overheatd. Water / Oil leakage e. Abnormal noise f. Others ( )

Phenomena at the time of the defect's occurrenceThe time when the fault began to occur

a. Since the vehicle was new b. Recently (From which month and year)c. After putting in for maintenance

Frequency of occurrence a. Always b. In certain conditions c. Occasionally

Weather Sunny · Cloudy · Rain · Snow · Thunderstorm Temperature Approximately �C Humidity Approximately %

Temperature conditions Coolant: a. When cool b. When warm Temperature inside engine room: �C

Operation conditions

a. No relation b. When idling c. When revving d. When acceleratinge. When travelling at constant speed f. When reducing speedg. When travelling uphillh. During material handling operations When not loaded (when steering · lifting · tilting) When loaded (Load weight: approx. kg) (when steering · lifting · tilting)i. Other (when using the inching brake · when steering · other)

Lamps a. Lights constantly b. Lights occasionally c. Does not light



Section 1.3.3

3-5

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DIAGNOSIS (SELF DIAGNOSIS FUNCTION)

GENERALWhen the computer detects a problem in the system, the fault is made known by a lighting a warning lamp anddisplaying an error code on the combination meter, while at the same time failsafe functions operate to stop theengine or control the engine to a low speed.

Diagnosis display system1. Diagnosis display system

The diagnosis is displayed by means of an error code asshown in the illustration to the left, and by the lights turning on.When the IG switch is turned ON, the lamp lights once to allowchecking for the bulb, and then turns off again if the status isnormal.When the IG switch is ON, if an abnormality occurs when thevehicle is stopped, travelling, or when it is performing materialshandling operations, on detection of the abnormality an errorcode is displayed, the engine light turns on, and the spannerlamp flashes as a warning.When this happens, stop the vehicle quickly and check theerror code.

2. Diagnosis display systemThe diag memory has a system using the hour meter and tilt lever, a system using the option display, and asystem using a plug-in analyzer.Here the display system using the hour meter and tilt lever is described.

(1) Open the diag memory menu from the main menu (Refer to 8FG Repair Manual).

(2) With each press and release of the knob switch, the respective error code and time of occurrence arealternately displayed at 2 second intervals.

Note:• The maximum number of error codes that can be in the memory is 10, and the smaller diag number

represents a newer error.• An error code appearing just when the key is turned ON may have its stored time such as 0.0.

(3) Connect the matching connector and turn the key switch to OFF.

Error code display

An orange colored lamp lights(Engine ECU only)

Lamp blinks

Knob switch

Diagnosis memory menu

Press the knob switch to return it.

Switches automatically every 2 seconds



Section 1.3.3

3-63-6

HOW TO INTERPRET THE FLOW-CHARTS

Turn the key switch OFF and ON again

NGDrive controller defect

Is there an error code 31-1?

Inspect the VF voltage.Standard: 2.5 ± 0.5 V

OK To next procedure depending on result

Single frames indicate measurement using a circuit tester and normal procedures.

Double frames indicate items that can be inspected using mask function.



Section 1.3.3

3-7

ANALYZER

EXPLANATIONAnalyzer function supports operations for inspecting/investigating faulty section by displaying the condition of thecontrol system, using communication between each controller and the multifunction display or plug-in analyzer.By switching the multifunction display to analyzer mode, or connect the plug-in analyzer to the diagnosis connector,operative conditions of the sensor actuator that is used for traveling functions, or the error information detected bythe controller can be read. This is very useful for checking operative condition of each function and saving time forrepairing when there is a defect.The analyzer functions can be used to make servicing faster and easier.Refer to 8FG series repair manual for how to use the analyzer functions.

The analyzer functions include the following functions.

1. Diagnosis memory function (DIAG MEMORY)The controller stores a maximum of the past 10 error codes (diagnosis codes) for faults that have occurred in theelectrical system. The diagnosis function is the function that reads these error codes and displays them on thedisplay.The error code and its time of occurrence as a key ON hour meter time are displayed on the display.

2. In/out monitor function (I/O MONITOR)This function displays the analog input value of each sensor relating to driving, material handling, FHRS, SAS,and OPS on the display. By monitoring this display it is possible to judge whether each circuit and sensor has afault or not.I/O ENGINE CTRL: The display shows various kinds of input value such as the analog input voltage from each

sensor to the controller, as well as control correction values and the status of the output tothe relay.



Section 1.3.3

3-83-8

ANALYZER MENU SCREEN LIST

ANALYZER MENU screen Display item DescriptionDIAG MEMORY 1. - 10. Indications of errors occurredI/O ENGINE CTRL IGSW Key switch (IG)

STA Key switch (ST)BATT Battery voltageG/LP Fuel changeover switchSEL Fuel specification discrimination signalADJ Engine specification discrimination signal

MREL EFI main relay drive signalFC Circuit opening relay drive signal

LPR LP gas main relay drive signalLFC LP gas slow solenoid drive signal

OXHT O2 sensor heater drive signalTHA Intake temperature sensor voltageTHW Coolant temperature sensor voltagePIM Intake pipe negative pressure sensor voltage

VPA1 Accelerator sensor (1) voltageVPA2 Accelerator sensor (2) voltage

PA Accelerator opening angleVTA1 Throttle position sensor (1) voltageVTA2 Throttle position sensor (2) voltage

TA Throttle opening angleIM Electronic throttle motor currentNE Engine speedIGT Ignition timing (spark advance amount)OX O2 sensor voltageVF VF voltage (LPG/CNG)

LINJ Injector correction value (LPG/CNG)FCM Air-fuel ratio motor correction value (LPG/CNG)



Section 1.3.3

3-9

ABOUT TROUBLE SHOOTING BY ERROR CODES1. Defective contact of connectors may cause error codes to appear and disappear. Therefore before performing

troubleshooting, check the battery cable connection, turn the key switch ON, and check that the error codeappears.If the error code does not appear, inspect the connection status of the relevant connector.

2. Once an error occurs, the error code is stored in the controller. Even if an error code appears only temporarilyand then disappears due to a defective contact, the error code will still be stored.

3. This volume contains a flow chart relating to symptoms that are particular to LPG.When an error code is showing, refer to 8FGU/8FDU15-32, 8FGCU20-32 Repair Manual Vol.1 (Pub. No.CU053) and 8FGCU15-18 Repair Manual Vol.2 (Pub. No. CU055) and perform inspection and repair first. Whenan error code is not showing, refer to the page for the relevant symptom and perform inspection and repair.



Section 1.3.3

3-10

TAB

LE O

F D

IAG

NO

SIS

CO

DES

Indi

catio

nM

emor

ySp

anne

rD

etec

tion

ECU

Erro

r mod

ePh

enom

enon

on

vehi

cle

01-3

01-3

Blin

king

4Y-E

CS

Fuel

feed

back

con

trol a

bnor

mal

ity (L

PG/C

NG

) ric

hTh

e en

gine

spe

ed is

uns

tabl

e an

d it

may

sto

p.01

-401

-4Bl

inki

ng4Y

-EC

SFu

el fe

edba

ck c

ontro

l abn

orm

ality

(LPG

/CN

G) l

ean

01-5

01-5

Blin

king

4Y-E

CS

O2

sens

or o

pen

abno

rmal

ityTh

e en

gine

spe

ed is

uns

tabl

e an

d it

may

sto

p.01

-601

-6Bl

inki

ng4Y

-EC

SO

2 se

nsor

hea

ter o

pen

abno

rmal

ityD

ispl

ay o

nly

02-1

02-1

Blin

king

4Y-E

CS

Inta

ke te

mpe

ratu

re s

enso

r-ope

n ab

norm

ality

The

engi

ne m

ay b

ecom

e ou

t of a

djus

tmen

t at l

ow

tem

pera

ture

s.02

-202

-2Bl

inki

ng4Y

-EC

SIn

take

tem

pera

ture

sen

sor s

hort

abno

rmal

ity03

-103

-1Bl

inki

ng4Y

-EC

SIn

take

pip

e pr

essu

re s

enso

r-ope

n ab

norm

ality

The

engi

ne m

ay b

egin

to ru

n ro

ugh

03-2

03-2

Blin

king

4Y-E

CS

Inta

ke p

ipe

pres

sure

sen

sor s

hort

abno

rmal

ity04

-104

-1Bl

inki

ng4Y

-EC

SW

ater

tem

pera

ture

sen

sor o

pen

abno

rmal

ityTh

e en

gine

may

bec

ome

out o

f adj

ustm

ent a

t low

te

mpe

ratu

res.

04-2

04-2

Blin

king

4Y-E

CS

Wat

er te

mpe

ratu

re s

enso

r sho

rt ab

norm

ality

05-1

05-1

Blin

king

4Y-E

CS

Thro

ttle

posi

tion

sens

or 1

ope

n ab

norm

ality

Lim

ited

spee

d of

trav

elin

g an

d m

ater

ials

han

dlin

g du

e to

lim

ited

engi

ne p

ower

out

put

05-2

05-2

Blin

king

4Y-E

CS

Thro

ttle

posi

tion

sens

or 1

sho

rt ab

norm

ality

05-3

05-3

Blin

king

4Y-E

CS

Thro

ttle

posi

tion

sens

or 2

ope

n ab

norm

ality

05-4

05-4

Blin

king

4Y-E

CS

Thro

ttle

posi

tion

sens

or 2

sho

rt ab

norm

ality

05-5

05-5

Blin

king

4Y-E

CS

Thro

ttle

posi

tion

sens

or o

ffset

abn

orm

ality

05-6

05-6

Blin

king

4Y-E

CS

Thro

ttle

posi

tion

sens

or o

ut o

f ran

ge a

bnor

mal

ity06

-106

-1Bl

inki

ng4Y

-EC

STh

rottl

e m

otor

driv

e ci

rcui

t ope

n ab

norm

ality

Lim

ited

spee

d of

trav

elin

g an

d m

ater

ials

han

dlin

g du

e to

lim

ited

engi

ne p

ower

out

put

06-2

06-2

Blin

king

4Y-E

CS

Thro

ttle

mot

or d

rive

circ

uit s

hort

abno

rmal

ity06

-306

-3Bl

inki

ng4Y

-EC

STh

rottl

e m

otor

pow

er s

uppl

y ci

rcui

t ope

n ab

norm

ality

06-4

06-4

Blin

king

4Y-E

CS

Thro

ttle

mot

or p

ower

sup

ply

circ

uit s

hort

abno

rmal

ity06

-506

-5Bl

inki

ng4Y

-EC

STh

rottl

e m

otor

sei

zing

abn

orm

ality

06-6

06-6

Blin

king

4Y-E

CS

Elec

troni

c th

rottl

e sy

stem

abn

orm

ality

07-1

07-1

Blin

king

4Y-E

CS

Air-f

uel r

atio

mot

or o

pen

abno

rmal

ityTh

e en

gine

spe

ed is

uns

tabl

e an

d it

may

sto

p.08

-108

-1Bl

inki

ng4Y

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w v

olta

ge (b

atte

ry li

ne o

pen)

abn

orm

ality

Dis

play

onl

y09

-109

-1Bl

inki

ng4Y

-EC

SIg

nitio

n si

gnal

abn

orm

ality

The

engi

ne s

peed

is u

nsta

ble

and

it m

ay s

top.

0A-1

0A-1

Blin

king

4Y-E

CS

Fuel

spe

cific

atio

n de

term

inat

ion

sign

al a

bnor

mal

ityD

ispl

ay o

nly

0A-2

0A-2

Blin

king

4Y-E

CS

Fuel

spe

cific

atio

n ch

ange

over

sw

itch

abno

rmal

ityD

ispl

ay o

nly

0A-3

0A-3

Blin

king

4Y-E

CS

Fuel

spe

cific

atio

n ty

pe d

oes

not m

atch

Engi

ne m

ay s

top

0A-4

0A-4

Blin

king

4Y-E

CS

Engi

ne s

peci

ficat

ion

dete

rmin

atio

n ab

norm

ality

Lim

ited

spee

d of

trav

elin

g an

d m

ater

ials

han

dlin

g du

e to

lim

ited

engi

ne p

ower

out

put



Section 1.3.3

3-11

18-1

18-1

Blin

king

4Y-E

CS

Cam

ang

le s

enso

r ope

n ab

norm

ality

Engi

ne s

top

ASC

Engi

ne s

peed

sen

sor o

pen

abno

rmal

ityPa

rtial

lim

itatio

n of

the

driv

e co

ntro

l fun

ctio

n.

18-2

18-2

Blin

king

4Y-E

CS

Cam

ang

le s

enso

r ope

n ab

norm

ality

(on

star

t up)

Engi

ne w

ill no

t sta

rtAS

CEn

gine

spe

ed s

enso

r GN

D s

hort

abno

rmal

ityPa

rtial

lim

itatio

n of

the

driv

e co

ntro

l fun

ctio

n.18

-318

-3Bl

inki

ng4Y

-EC

SC

rank

ang

le s

enso

r ope

n ab

norm

ality

Dis

play

onl

yAD

-2AD

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inki

ng4Y

-EC

SC

AN c

omm

unic

atio

n SA

S/O

PS d

ata

rece

ptio

n ab

norm

ality

Parti

al li

mita

tion

of th

e dr

ive

cont

rol f

unct

ion.

C4-

1C

4-1

Blin

king

4Y-E

CS

Acce

lera

tor s

enso

r 1 o

pen

abno

rmal

ity

Lim

ited

spee

d of

trav

elin

g an

d m

ater

ials

han

dlin

g du

e to

lim

ited

engi

ne p

ower

out

put

ASC

C4-

2C

4-2

Blin

king

4Y-E

CS

Acce

lera

tor s

enso

r 1 s

hort

abno

rmal

ityAS

C

C4-

3C

4-3

Blin

king

4Y-E

CS

Acce

lera

tor s

enso

r 2 o

pen

abno

rmal

ityAS

C

C4-

4C

4-4

Blin

king

4Y-E

CS

Acce

lera

tor s

enso

r 2 s

hort

abno

rmal

ityAS

C

C4-

5C

4-5

Blin

king

4Y-E

CS

Acce

lera

tor s

enso

r offs

et a

bnor

mal

ityAS

CC

4-6

C4-

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inki

ng4Y

-EC

SAc

cele

rato

r sen

sor o

ut o

f ran

ge a

bnor

mal

ity

Indi

catio

nM

emor

ySp

anne

rD

etec

tion

ECU

Erro

r mod

ePh

enom

enon

on

vehi

cle



Section 1.3.3

3-123-12

TROUBLESHOOTING BY SYMPTOMSSymptom Chart

Charts by System

Symptom Page for referenceDoes not start Starting motor turns over but engine does not start 3-13

Poor idle adjustmentUnstable idle speed 3-15Idle speed low and unstable 3-17Idle speed high 3-18

Poor drivabilityKnocking 3-19Hesitation 3-20Insufficient power output 3-22

Engine stall

Engine stalling in general 3-25Engine stalling a short time after start up 3-28Engine stalling when A/C, lights, or defogger are turned on, or when the steering is operated 3-30

Engine stalling on releasing the accelerator 3-31

LPG injector system 3-33Air-fuel ratio control motor system 3-35Slow solenoid valve system 3-36



Section 1.3.3

3-13

� <DOES NOT START> STARTING MOTOR TURNS OVER BUT ENGINE DOES NOT STARTProbable cause

• Ignition system defect (When combustion does not start)• Fuel system defect (When combustion does start, but does not continue.)• Regulator primary pressure abnormality during cranking (When the pressure is high there is a possibility of rich

air-fuel ratio)

Note:When low vapour pressure LPG fuel is used in winter, engine may stall when longer idling or while travelingand be difficult to start immediately afterwards. In this case pour warm water over the LPG regulator tovaporize the fuel, and at the same time turn the LPG switch OFF to stop the fuel supply momentarily andcrank after fully opening the accelerator.

Inspect the ignition system.(Refer to parts inspection and adjustment 10, 11, 12, 13)

Inspect LPG injector piping internal pressure

(1) Disconnect the fuel hose between the LPG regulator and the LPG injector at the regulator side.

(2) Connect the SST to the LPG regulator, and inspect the pressure during cranking.SST 09820-23600-71

Standard: The pressure rises.

SST

Replace LPG filter

NG

OK

Replace main solenoid valveOK

NG

Inspect ignition

Inspect LPG filter

Inspect main solenoid valve operating noiseInspect the operation sound of the solenoid valve when the ignition switch is turned ON.Standard: The valve makes an operation noise

Inspect the wire harness and connectors to the main solenoid valve. (Refer to the wiring diagram at the back of the book)

Repair wire harness and connectors

NG

OK

NG

OK

OK NG

Replace slow solenoid valveOK

NG

Inspect slow solenoid valve operating noiseInspect the operation sound of the solenoid valve when the ignition switch is turned ON.Standard: The valve makes an operation noise

Inspect the wire harness and connectors to the slow solenoid valve. (Refer to the wiring diagram at the back of the book)


NG

OK



Section 1.3.3

3-143-14

OK

Inspect LPG regulator primary pressure (Refer to parts inspection and adjustment 1)

Repair or replace LPG regulator

OK

NG

NG

Defect of ignitor or engine ECU

Adjust primary pressure of LPG regulator.(Refer to parts inspection and adjustment 2)

Check starting abilityNG

OK

Finish



Section 1.3.3

3-15

� <POOR IDLE ADJUSTMENT> UNSTABLE IDLE SPEEDProbable cause

• Air leakage• 1 or more cylinders misfiring• VF voltage abnormality during idling• Ignition timing off

Note:When fuel of a low vapor pressure is used in winter, insufficient vaporization may cause unstable idle speed.

Inspect inner vent piping and LPG regulator drain cock

STD.

OPT.

(1) Inspect the installation of the inner vent piping.Standard: Connected.(2) Remove the drain plug (STD.), or open the LPG regulator drain cock

(OPT.), remove any tar and close the drain cock again.Caution:

Be sure to intall the drain plug (STD.), or close the cock after removing tar. Drain plug

Close

Open

Replace spark plugNG

OK

Inspect power balanceCause one cylinder at a time to misfire by removing its resistive cord, and inspect for a drop in idle speed.

Inspect distributor cap and resistive cord (Refer to parts inspection and adjustment 10, 11)

Only a particular cylinder NG

OK

Inspect spark plugs(1) Check that there is no obvious

deposition.(2) Inspect the plug gap.Standard: 0.7 to 1.0 mm (0.028 to 0.039 in)

Inspect for air leakage between the throttle body and cylinder head.

Repair air leak

NGReplace distributor cap and resistive cord

NG

OK

OK

Inspect compression(Refer to parts inspection and adjustment 15)

Inspect initial advance timing (Refer to page 2-16)

NG Adjust initial advance timing

OK



Section 1.3.3

3-163-16

Inspect VF voltage(Refer to parts inspection and adjustment 14)

Standard: 2.5 ± 0.5VOK

NG Adjust VF voltage

To injector system (Refer to 3-32)

OK

Engine ECU defect

NG

OK

Switch to a fuel with high vaporization pressure and inspect the idle speed.(Winter only)

Fuel is defectiveNG

Inspect injector function(Refer to parts inspection and adjustment 6)

OK

Inspect and repair engineNGInspect compression(Refer to parts inspection and adjustment 15)

OK

Replace distributor cap and/or resistive cordNGInspect distributor cap and resistive cord(Refer to parts inspection and adjustment 10, 11)

OK

Replace ignition coilNGInspect ignition coil(Refer to parts inspection and adjustment 12)

OK

Clean or replace LPG filterNGInspect LPG filter

OK


NGInspect LPG regulator primary pressure(Refer to parts inspection and adjustment 1)

OK

Repair LPG regulator (Refer to section 2)

NGInspect LPG regulator (secondary system)(Refer to page 2-5)

OK

Clean or replace spark plugNGInspect spark plugs(1) Check that there is no obvious deposition.(2) Inspect the plug gap.Standard: 0.7 to 1.0 mm (0.028 to 0.039 in)



Section 1.3.3

3-17

� <POOR IDLE ADJUSTMENT> IDLE SPEED LOW AND UNSTABLEProbable cause

• Air-fuel ratio over-lean• Blockage around the electric throttle valve

OK

Check whether the engine idle speed changes.

Inspect the VF voltage.(Refer to parts inspection and adjustment 14)

Standard: 2.5 ± 0.5 VNote:A over-lean air-fuel ratio may result in a low and unsable idle speed.

NG Adjust VF voltage

Finish

Idle speed gradually increases to within standard value

Inspect electronic throttleOperate the accelerator pedal and inspect to see that the throttle PA value changes smoothly.Standard: PA value changes smoothly.

The idle speed remains low and does not change

NG • Check throttle system• Clean or replace electric throttle

OK

Inspect LPG regulatorCheck LPG regulator for tar accumulation and drain plug loosening/cock openingStandard: Tar is not accumulated and plug is not loosened/cock is not opened

NG • Tighten drain plug/close cock• Clean LPG regulator

(Refer to section 2)

OK

Check adaptor for tar accumulationNG Clean adaptor

OK

Inspect FCM operation(Refer to parts inspection and adjustment 5)

NGClean or replace FCM

OK

Replace engine ECU



Section 1.3.3

3-183-18

� <POOR IDLE ADJUSTMENT> IDLE SPEED HIGHProbable cause

• Throttle valve return defect• Air leakage• VF voltage abnormality

Note:Inspect parts related to the items listed above.



Section 1.3.3

3-19

� <POOR DRIVABILITY> KNOCKINGProbable cause

• Excess deposition in combustion chamber or on spark plug electrode• Ignition timing off

OK

Excess deposition in combustion chamber, or on piston head portion

Replace spark plugNGInspect spark plugs(1) Check that there is no obvious deposition.(2) Inspect the plug gap.Standard : 0.7 to 1.0 mm (0.028 to 0.039 in)

Adjust initial advance timing(Refer to page 2-16)

NGCheck initial advance timing(Refer to page 2-16)

OK



Section 1.3.3

3-203-20

� <POOR DRIVABILITY> HESITATIONProbable cause

• Electronic throttle abnormality• VF voltage abnormality• Initial advance timing off• O2 sensor abnormality

Caution:Since pulsating combustion occurs on fuel cut operation at high rpm, operate in a range below the rpm atwhich hesitation occurs.

Reference:When not loaded: Rated no-load maximum speedWhen traveling: Rated under-load maximum speed

Inspect initial advance timing(Refer to page 2-16)Standard: 7.0�

OK

Inspect throttle system

Inspect electronic throttleOperate the accelerator pedal and inspect to see that the throttle PA value changes smoothly.Standard: PA value changes smoothly.

Replace LPG filterNGInspect LPG filter

OK

NG

OK

Inspect VF voltage (Refer to parts inspection and adjustment 14)Inspect changes in VF voltage and OX value (0 or 1) at 1800 r/min. (idle OFF).Standard: 2.5 ± 0.5 V*

NG

OK

NG Adjust initial advance timing

Inspect, repair, or replace the feedback-related components (injectors, O2 sensor, etc.) and the relevant wire harnesses and connectors (Refer to parts inspection and adjustment)

*: 0 V, 2.50 V, or 5.0 V will be displayed when the plug-in analyzer is used for the inspection.



Section 1.3.3

3-21

Inspect distributor cap and resistive cord(Refer to parts inspection and adjustment 10, 11)

OK

Repair or replaceNGInspect wire harness and connectors related to the air-fuel ratio controll system

OK

Repair or replaceNGInspect inner vent system(1) Check inner vent tube for damage, bent or

disconnection(2) Check resonator for damage

Inspect O2 sensor feedback(Refer to parts inspection and adjustment 14)

Inspect LPG regulator primary pressure (Refer to parts inspection and adjustment 1)

OK

NG Adjust primary pressure of LPG regulator (Refer to parts inspection and adjustment 2)

To injector system (3-33)NGInspect injector operation and inspect for blockages (Refer to parts inspection and adjustment 6, 7)

OK

O2 Sensor system defectNG

OK

Replace distributor cap and resistive cordNG

OK


OK

To air-fuel ratio control motor system(Refer to page 3-35)

NGInspect air-fuel ratio control motor operation(Refer to parts inspection and adjustment 5)

OK

OK


Replace engine ECU



Section 1.3.3

3-223-22

� <POOR DRIVABILITY> INSUFFICIENT POWER OUTPUTProbable cause

• Air-fuel ratio abnormality (over-lean)• Initial advance timing off

Note:• After disconnecting the battery terminal or removing the LPG fuse, the fuel system learning value will be

cleared. This may cause temporary insufficient power output. (Power output will return after beingdriven for a short while.)

• If a fuel with low pressure vaporization is used in winter, it is possible that the air-fuel ratio may beabnormal (over-rich).

Inspect O2 sensor feedback(Refer to parts inspection and adjustment 14)

Inspect water temperature (THW)

Inspect LPG filter

OK

NG Replace LPG filter

Inspect, identify fault, and repair, cleaning system

NG

OK

Repair vacuum pipingNGInspect vacuum piping of vacuum sensorStandard: No hoses disconnected, blocked or bent

OK


NGInspect initial advance timing(Refer to page 2-16)

OK

O2 Sensor system defectNG

OK

Inspect electronic throttle systemNGInspect the full open status of the throttle valveInspect the aperture (TA) of the throttle valve when the accelerator pedal is depressed once.Standard: 96 %

OK

Repair or replaceNGInspect inner vent system(1) Check inner vent tube for damage, bent or


OK



Section 1.3.3

3-23

OK

Repair wire harness between engine ECU - LPG fuse(Refer to the wiring diagram at the back of the book)

NGInspect battery voltage (BATT)Standard: 10 to 14 V

OK

NG

Inspect VF voltage (Refer to parts inspection and adjustment 14)Inspect changes in VF voltage and OX value (0 or 1) at 1800 r/min. (idle OFF).Standard: 2.5 ± 0.5 V*

OK


OK

Inspect and repair engine bodyNGInspect compression(Refer to parts inspection and adjustment 15)

OK

Replace distributor cap and resistive cordNGInspect distributor cap and resistive cord(Refer to parts inspection and adjustment 10, 11)

OK


OK

Replace vacuum sensorOKDuring idling, measure the voltage between PIM - E2 of the engine ECU.Standard: 3.0 to 4.0 V (For engine stop)

Disconnect the vacuum sensor connector and measure the voltage between VC - E2 terminals of the vehicle harness.Standard: 4.5 to 5.0 V

NG





Section 1.3.3

3-243-24

Repair LPG regulator(Refer to section 2)

NG (Standard value or more, or not airtight)Inspect LPG regulator primary pressure

(Refer to parts inspection and adjustment 1)

OK

• LPG regulator (secondary system) defect• Engine ECU defect• Or unsuitable fuel used (winter only)

Inspect and repair blockages in fuel piping system

OK

Repair wire harness connectors

NG

Inspect wire harness and connectors between engine ECU and vacuum sensor(Refer to the wiring diagram at the back of the book)

NG

Replace engine ECU

OK


NG (Standard value or below)

OK NG

Finish



Section 1.3.3

3-25

� <ENGINE STALL> ENGINE STALLING IN GENERALProbable cause

• Charging system• LPG regulator primary pressure adjustment defect• Air leak in (over-lean) intake system• Ignition timing defect• Idling air-fuel ratio adjustment defect• LPG slow solenoid defect• Injector defect

Note:• Pay attention to the warning light lighting when the engine stall occurs.• Be careful about inappropriate LPG in winter (low vaporization pressure).• When using low vaporization pressure fuel, if the engine stalls during idling, or when travelling when the

engine is not sufficiently warmed up, there is a high possibility that the air-fuel ratio is over-rich. Openthe accelerator up fully and crank it for a while, and wait for the engine to start.

• Combination meter power supply• Inspect and repair charge warning light

Stays offCheck the charge warning lamp

Light comes on during engine stall

Check the "check engine" warning light

Inspect and repair charging systemLight comes on before engine stall

Inspect LPG filter Clean or replace LPG filter

Light comes on during engine stall

Stays off Inspect the "check engine" warning light by short circuiting between the engine ECU MZL - E1 terminals.Standard: Turns on

NGInspect and repair the "check engine" warning lamp system

Inspect the engine ECU

Light comes on before engine stall

OK

Measure the voltage between +B - E1 terminals of the engine ECU.Standard: 10 to 14 V

NG Replace engine ECU

Measure the voltage between IGSW - E1 terminals of the engine ECU.Standard: 10 to 14 V (Ignition switch ON)

NG Inspect and repair the ignition switch system

OK

OK

Measure the voltage between MREL - E1 terminals of the engine ECU.Standard: 10 to 14 V (Ignition switch ON)

NG Replace engine ECU

Inspect and repair the main relay system

OK

NG

OK



Section 1.3.3

3-263-26

Inspect ignitionNG (Does not start at all)

Check the vehicle re-starts

Recreation testOK

Inspect for air leakage between the adapter and cylinder head.

Repair air leakNG

OK



Inspect and repair ignition system

OK

Inspect initial advance timing (Refer to 2-13)

Adjust initial advance timingNG

OK


NG

OK

OK NG

LPG regulator defect or unsuitable fuel used (winter only)

Inspect slow solenoid valve(Refer to parts inspection and adjustment 4)

To slow solenoid valve system(Refer to page 3-36)

NG

OKInspect injector system operation and inspect for blockages(Refer to parts inspection and adjustment 6, 7)

To injector system(Refer to page 3-33)

NG (Non-operational)

NG (Outside standard value)

OK




Section 1.3.3

3-27

Inspect LPG regulator primary pressure(Refer to parts inspection and adjustment 1)

LPG regulator (secondary system) defect or unsuitable specification fuel (winter only)

OK

NG (Outside standard value)

Adjust LPG regulator primary pressure (Refer to parts inspection and adjustment 2)

Inspect and repair blockages in fuel piping system

NG

OK

Check that the engine restarts

OK

Finish

Repair LPG regulator (Refer to section 2)

NG (Airtightness defect)



Section 1.3.3

3-283-28

� <ENGINE STALL> ENGINE STALLING A SHORT TIME AFTER START UPProbable cause

• LPG regulator primary pressure adjustment defect• Blocked injector, air control valve, or by-pass route• Charging system defect• LPG solenoid defect• Fuel supply cut

Note:• Pay attention to the fuel used during winter.

Inspect the wire harness and connectors of the main solenoid valve.(Refer to the wiring diagram at the back of the book)

NG

OK

Does the engine re-start?Inspect main solenoid valve operating noiseInspect the solenoid valve operation noise when the ignition switch is turned ONStandard: The valve makes an operation noise

NG

NG


Inspect and repair the charger

Replace main solenoid valve

Inspect the charge warning light

Inspect LPG injector piping internal pressure

(1) Disconnect the fuel hose between the LPG regulator and the LPG injector at the regulator side.

(2) Connect the SST to the LPG regulator, and inspect the pressure during cranking.SST: 09820-23600-71

Standard: The pressure rises.

SST

Repair or replace LPG regulator (See section 2)

NGOK

NG

OK

OK

OK

Inspect the wire harness and connectors of the slow solenoid valve.(Refer to the wiring diagram at the back of the book)

NG

OK

Inspect slow solenoid valve operating noiseInspect the slow solenoid valve operation noise when the ignition switch is turned ONStandard: The valve makes an operation noise


Replace slow solenoid valve

NG

OK



Section 1.3.3

3-29


Inspect changes in VF voltage and OX value (0 or 1) at 1800 r/min. (idle OFF).Standard: 2.5 ± 0.5 V*

Adjust initial advance timingNGInspect initial advance timing(Refer to page 2-16)

OK

NG

OK

Clean or replace LPG filterNGInspect LPG filter(Refer to page 2-8)

OK

Adjust primary pressure of LPG regulator(Refer to parts inspection and adjustment 2)


OK

• Unsuitable fuel used• Engine ECU defect





Section 1.3.3

3-303-30

� <ENGINE STALL> ENGINE STALLING WHEN A/C, LIGHTS, OR DEFOGGER ARE TURNED ON, OR WHEN THE STEERING ISOPERATEDProbable cause

• LPG regulator primary pressure adjustment defect• Pay attention to air-fuel ratio abnormalities (injector blocked, idle adjustment defect)• Battery defect



NG

OK*: 0 V, 2.50 V, or 5.0 V will be displayed when the plug-in analyzer is used for the inspection.


Repair or replaceNG

Inspect inner vent system(1) Check inner vent tube for damage, bent or


Charge or replace the batteryNGInspect battery voltage (BATT)Standard: 10 to 14 V

OK


NGInspect initial advance timing(Refer to page 2-16)

OK

Adjust primary pressure of LPG regulator(Refer to parts inspection and adjustment 2)


OK

• Inspect LPG regulator (secondary system)(Refer to page 2-10)

OK



Section 1.3.3

3-31

� <ENGINE STALL> ENGINE STALLING ON RELEASING THE ACCELERATORProbable cause

• Idling air-fuel ratio adjustment defect• Ignition timing off• Air leakage• Injector defect• LPG filter defect



OK

Adjust initial advance timingNGInspect initial advance timing(Refer to page 2-16)

OK

To slow solenoid valve system(Refer to page 3-36)

NGInspect slow solenoid valve(Refer to parts inspection and adjustment 4)

OK

Inspect distributor pickup coil(Refer to parts inspection and adjustment 12)

YESDoes knocking occur on racing of the engine?

NG

Repair air leakNGInspect the air intake system for air leaks

OK

Replace distributor pickup coil

OK

Inspect wire harness and connectors between engine ECU - pickup coil (Refer to wiring diagram)

NG


OK

Inspect or replace engine ECU

NO

NG

Replace main solenoid valveNGInspect main solenoid valve(Refer to parts inspection and adjustment 3)

OK





Section 1.3.3

3-323-32

Engine ECU defect

OK

To LPG injector system(Refer to page 3-33)

NGInspect injector system operation and inspect for blockages(Refer to parts inspection and adjustment 6, 7)

OK

Adjust LPG regulator primary pressureNGInspect LPG regulator primary pressure(Refer to parts inspection and adjustment 1)

OK

Replace LPG filterNGInspect LPG filter



Section 1.3.3

3-33

� LPG INJECTOR SYSTEM

Measure the voltage between INJ - E1 terminals of the engine ECU.Standard: 10 to 14 V

OKInspect LPG injectors(Refer to parts inspection and adjustment 6, 7)

NG

Inspect the solenoid resistor(1) Inspect the resistance

value of the solenoid resistor.

Standard: 5.7 to 6.3 � (20°C) [68°F]

NG Replace the solenoid resistor

OK

Inspect the wire harness and connectors between engine ECU - solenoid resistor(Refer to the wiring diagram at the back of the book)

NG Repair wire harness and connectors

OK


Clean or replace injectorsNGInspect the injectors for air-tightness

(Refer to parts inspection and adjustment 6)

OK

Perform startup operation inspection and idle operation inspection of injectors. (Refer to parts inspection and adjustment 6)


Inspect and repair the STA system

OK

To *ANG (Only during startup)

To *BNG

Measure the voltage between RES - E1 terminals of the engine ECU.Standard: 10 to 14 V

NG

OK

Inspect LPG injectors(Refer to parts inspection and adjustment 6, 7)

Measure the voltage between INJ - E1 terminals of the engine ECU.Standard: 10 to 14 V

NG Inspect wire harness and connectors between INJ - E1 of the engine ECU


OK


Measure the voltage between STA - E1 terminals of the engine ECU.Standard: 10 to 14 V

OK

*A

NG

Clean or replace injectors



Section 1.3.3

3-343-34

Inspect voltage between connectors on vehicle wire harness side with injector connector disconnected

(1) Disconnect the injector connector.(2) Turn the ignition switch on.(3) Inspect the voltage between connector terminals on

the vehicle wire harness side when the engine is stopped and when it is idling.

Standard: When engine is stopped 0 VWhen engine is raced Pulsation occurs


NG

Inspect and replace injectors(Refer to parts inspection and adjustment 6, 7)

Inspect wire harness and connectors between engine ECU and injectors(Refer to the wiring diagram at the back of the book)

OK

OK

Inspect voltage between connector 1 terminal on vehicle wire harness side and body earth, with injector connector disconnected

(1) Turn the ignition switch on.(2) Inspect voltage between connector 1 terminal on vehicle wire

harness side and body earth.Standard: 10 to 14 V (Battery voltage)

OK

Inspect and repair injector power supply system

NG


NG

Measure the voltage between the THW - E1 terminals of the engine ECU.Standard: 4.5 to 5.5 V

OKReplace engine ECU

NG

Inspect the coolant temperature sensor (Refer to parts inspection and adjustment 9)

NG Replace coolant temperature sensor

OK

Inspect wire harness and connectors between the engine ECU and coolant temperature sensor(Refer to the wiring diagram at the back of the book)

OK

Replace engine ECU

Inspect injector operation with the coolant temperature sensor connector disconnected.

(1) Disconnect the connector from the coolant temperature sensor.

(2) With the engine idling, disconnect the injector connector and check the idling condition.

Standard: The engine speed decreases.

OK

NG

*B

NG Repair wire harness and connectors



Section 1.3.3

3-35

� AIR-FUEL RATIO CONTROL MOTOR SYSTEM

OKInspect air-fuel ratio control motor operation(Refer to parts inspection and adjustment 5)

NG

System normal

Disconnect the intake temperature sensor and carry out the above inspection again

Inspect the input voltage of the air-fuel ratio control motor

(1) Disconnect the connectors of the air-fuel ratio control motor.

(2) Turn the ignition switch on.(3) Inspect the voltages between the connector

terminals 2 and 5 on the wire harness side and body earth.

Standard: Between terminal 2 - body earth10 to 14 V (Battery voltage)Between terminal 5 - body earth10 to 14 V (Battery voltage)

NG

Inspect and replace engine control computer

OKMeasure the voltage between THA - E2 terminals of the engine control computerStandard: 0.5 to 3.5 V (When cold)

0.2 to 1.0 V (When warm)

OK

NG

Replace intake temperature sensor

NGInspect intake temperature sensor(Refer to parts inspection and adjustment 8)

OK


Inspect wire harness and connectors between the engine ECU and intake temperature sensor(Refer to the wiring diagram at the back of the book)

OK



OK

Inspect and repair the power supply system for the air-fuel ratio control motor

Inspect wire harness and connectors between engine ECU - air-fuel ratio control motor(Refer to the wiring diagram at the back of the book)

NG

NG

OK

Inspect air-fuel ratio control motor(Refer to parts inspection and adjustment 5)

OK

Replace air-fuel ratio control motor

NG


NG



Section 1.3.3

3-363-36

� SLOW SOLENOID VALVE SYSTEM

NGInspect slow solenoid valve for airtightness(Refer to parts inspection and adjustment 4)

OK

Replace slow solenoid valve

OKInspect slow solenoid valve operation(Refer to parts inspection and adjustment 4)

NG

System normal


Inspect wire harness and connectors between engine ECU - slow solenoid valve(Refer to the wiring diagram at the back of the book)

OK

Inspect voltage between connector terminal 2 on the slow solenoid valve wire harness side and body earth.

(1) Disconnect the connectors of the slow solenoid valve.(2) Inspect the voltage between the connector terminal 2 on the

wire harness side and body earth when the ignition switch is turned ON.

Standard: Momentarily 10 to 14 V (Battery voltage)

OK

Inspect and repair the power supply system for the slow solenoid valve

NG

Repair wire harness and connectorsNG

Inspect voltage between connector terminal 2 and terminal 1 on the slow solenoid valve wire harness side.

(1) Disconnect the connectors of the slow solenoid valve.(2) Inspect the voltages between the connector terminal

2 - terminal 1 on the wire harness side when the ignition switch is turned ON.

Standard: Momentarily 10 to 14 V (Battery voltage)

NG

Inspect and replace the slow solenoid valveOK

Slow solenoid valve harness side



Section 1.3.3

3-37

PARTS INSPECTION AND ADJUSTMENT1. Check LPG regurator primary pressure.

(1) Remove the tamper proof ring. (Refer to 2-5-1)

(2) Install the SST to the LPG regulator.

SST 09817-23600-71 ......................... (1)09820-23600-71 ......................... (2)

(3) Crank the engine.

(4) Check the LPG regulator primary pressure.

Standard:24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) [3.6 to 5.0 psi]

Note:The pressure remains as above one.

2. Adjust LPG regurator primary pressure

(1) Remove the tamper proof ring. (Refer to 2-5-1)

(2) Turn the ignition switch ON.

(3) Loosen the adjust screw nut and adjust the primarypressure by turning the screw.

Standard:24.5 to 34.3 kPa (0.25 to 0.35 kgf/cm2) [3.6 to 5.0 psi]

(4) Adjust the VF voltage. (See step 14.)

3. Inspect main solenoid valve


(2) Check the solenoid valve operating sound.

Standard: Solenoid valve makes operating sound.

(3) Disconnect the solenoid connector.

(4) Measure the resistance of the solenoid valve.

Standard resistance: 8.0 to 9.0 � (20�C) [68�F]

SST (2)

SST (1)

12



Section 1.3.3

3-383-38

4. Inspect slow solenoid valve

(1) Disconnect the injector hose from the LPG injector.

(2) Turn the ignition switch ON and OFF promptly.

(3) Check that the LPG blows.

Standard: LPG blows for a split second.

(4) Turn the ignition switch OFF.

(5) Disconnect the solenoid connector.


(7) Check for the LPG leakage.

Standard: No leakage occurs.

5. Inspect air fuel ratio control motor


(2) Put a sound scope on the air fuel ratio control motor.

(3) Check the air fuel ratio control motor operating sound.

Standard: Motor makes click sound for several seconds.

(4) Remove the air fuel ratio control motor.

Note:Do not disconnect the connector.

(5) Put masking tape on the contact surface with the adaptor,to prevent air from blowing.

(6) Measure the length (A) when the engine stops and isidling.

Standard: 13 to 14 mm (0.51 to 0.55 in) when engine stops14 to 18 mm (0.55 to 0.71 in) when engine is idling

Notice:Do not apply excessive force to the needle valve portion.



Section 1.3.3

3-39

(7) Disconnect the connector from the FCM.

(8) Measure the resistance between the terminals.

Standard:

Note:Cold temp. = -10 to 50�C (14 to 122�F)Hot temp. = 50 to 100�C (122 to 212�F)

(9) Check the air fuel ratio control motor operation.

(a) Apply battery positive (+) voltage to the terminal 2,negative (-) voltage to terminals in the order of 1, 3,4, and 6.

(b) Check that the needle valve movement.

Standard: The needle valve gradually moves to the CLOSE side.

(c) Apply battery positive (+) voltage to the terminal 5,negative (-) voltage to terminals in the order of 1, 3,4, and 6.

(d) Check that the needle valve movement.

Standard: The needle valve gradually moves to the OPEN side.

Notice:Do net apply excessive force to the needle valve portion.

123

456

Terminals Resistance

2-1, 3 15 to 25 � at cold temp.20 to 30 � at hot temp.

5-4, 6 15 to 25 � at cold temp.20 to 30 � at hot temp.

CLOSE side

OPEN side



Section 1.3.3

3-403-40

6. Inspect LPG injector

(1) Put a sound scope on the LPG injector.

(2) Check the injector operating sound while cranking theengine.

Standard: Injector makes operating sound.

Reference: Injector injects fuel twice per engine revolution whilecranking.


(4) Lightly pinch the injector hose with fingers and check thepulsation.

Standard: Pulsation occurs continuously.

(5) Check the idle condition when disconnecting the injectorconnector.

Standard: The engine idle speed decreases when disconnecting theconnector.

(6) Check air tightness of the LPG injector.

(a) Disconnect the LPG injector connector and removethe injector with the hose connected.

Note:Do not disconnect the injector hose.

(b) Check for the leakage of LPG from the injector whileturning the ignition switch ON and OFF.

Standard: No leakage occurs.

(7) Measure the resistance of the LPG injector.

Standard: 3.5 to 4.5 � at 20�C (68�F)

12



Section 1.3.3

3-41

7. Clean LPG injector

(1) With a clean shop rag, wipe off the carbon around thenozzle.

(2) Insert and desert a wire with diameter of less than 1.2 mm(0.047 in), while applying compressed air of 343 to 490kPa (3.5 to 5.0 kgf/cm2, 49.8 to 71.1 psi) from the intakeport.

Notice:Insert the wire within the range of 20 mm (0.79 in).

8. Inspect air temperature sensor

(1) Remove the air temperature sensor.

(2) Measure the resistance of the sensor.

Standard:

9. Inspect coolant temperature sensor

(1) Remove the coolant temperature sensor.

(2) Measure the resistance of the sensor.

Standard:

Temperature Resistance20�C (68�F) 2 to 3 k�

80�C (176�F) 0.2 to 0.4 k�

Temperature Resistance20�C (68�F) 2 to 3 k�

80�C (176�F) 0.2 to 0.4 k�



Section 1.3.3

3-423-42

10. Inspect distributor cap

(1) Check the distributor cap and center piece contactvisually.

Standard: • There is no crack on the distributor cap.• There is no damage on the center piece.• Center piece moves smoothly.• The cap inside is not considerably dirty.

11. Inspect resistive code

(1) Measure the resistance of the resistive codes.

Standard: 25 k�

12. Inspect ignition coil

(1) Disconnect the 4 resistive codes from the spark plug.

(2) Remove the distributor cap.

(3) Remove the distributor rotor.

(4) Remove the dust-proof cover.

(5) Inspect the primary coil.

(a) Measure the resistance between the terminals A andC.

Standard:

(6) Inspect the secondary coil.

(a) Measure the resistance between the terminals B andC.

Standard:

(7) Inspect the insulation of the ignition coils.

(a) Measure the resistance between the terminal A andbody ground D.

Standard: 1 M� or higher

Condition ResistanceCold 20�C (68�F) 0.33 to 0.55 �Hot 80�C (176�F) 0.42 to 0.65 �

Condition ResistanceCold 20 �C (68 �F) 6.7 to 12.9 k�Hot 80 �C (176 �F) 8.6 to 15.1 k�



Section 1.3.3

3-43

13. Inspect signal generator

(1) Disconnect the pickup coil connector.

(2) Measure the resistance between the terminals.

Standard:

(3) Remove the distributor cap, rotor, and dust-proof cover.

(4) Using a feeler gauge, measure the air gap between thesignal rotor tooth and pickup coil projection.

Standard: 0.2 to 0.4 mm (0.008 to 0.016 in)

14. Adjust VF voltage

(1) Warm up the heated oxygen sensor by maintaining theengine speed at 1800 rpm for approximately 2 minutes.

(2) Using plug-in analyzer or multi-function display, checkthat OX value alternates between 0 and 1.

Note:Maintain the engine rpm at 1800 rpm.

Standard: The OX value alternates more than 4 times, between 0 and1 for 10 seconds.

(3) Measure the VF voltage while engine idling.

Standard: 2.5 ± 0.5 V

(4) If the VF voltage is not within the specified range, adjustthe VF voltage to the specified value by turning the idleadjust screw slowly.

Reference:

(5) After racing the engine several times, check that the VFvoltage is within the specified range.

Note:Adjust the VF voltage to nearly 2.5 V.

12 Condition ResistanceCold 20�C (68�F) 370 to 550 �Hot 80�C (176�F) 475 to 650 �

VF voltage

OX value

COUNTERCLOCKWISE CLOCKWISEVF voltage Condition Measures

0V Air fuel ratio: RICH Turn the screw CLOCKWISE

5V Air fuel ratio: LEAN Turn the screw COUNTERCLOCKWISE



Section 1.3.3

3-443-44

15. Check cylinder compression pressure

(1) Warm up the engine to the normal operating temperature.

(2) Disconnect the distributor connectors.

(3) Disconnect the resistive codes from the spark plugs.

(4) Remove the spark plugs.

(5) Check the cylinder compression pressure.

(a) Install a compression gauge into the spark plug hole.

(b) Fully depress the accelerator pedal.

(c) While cranking the engine, measure thecompression pressure.

Standard: 1000 to 1373 kPa (10.2 to 14.0 kgf/cm2) [145 to 199 psi]

Note:The difference between each cylinder is within 196 kPa (2.0kgf/cm2) [28 psi]

(d) If the cylinder compression in 1 or more cylinders islow, pour a small amount of engine oil into the sparkplug hole and perform steps (a) through (c) for thecylinders with low compression.• If the compression pressure increases, piston

rings and/or cylinder bore may be worn ordamaged.

• If the compression stays low, valves may besticking, valve seating may be improper, or gasleakage through the gasket may occur.



Section 1.3.3

4-1

0123456789

101112131415161718192021E

APPENDIXPage

SST LIST ................................................................4-2SERVICE STANDARDS .........................................4-4WIRING DIAGRAM.................................................4-5

04.book 1 ページ２００７年２月２２日　木曜日　午後４時４８分


Section 1.3.4

4-24-2

SST LIST

Illustration Part number Part nameSection

2 3

09238-13130-71 Sub harness � �

09814-22000-71 Tool � �

09815-22000-71 Tool � �

09813-26600-71 Gauge � �

80339-76026-71 Automatic choke pipe plug � �

09817-23600-71 Union � �

09819-22000-71 Gauge � �



Section 1.3.4

4-3

0123456789

101112131415161718192021E

Illustration Part number Part nameSection

2 3

09819-23600-71 Gauge � �

23627-22000-71 Spring � �

09820-23600-71 Tester SUB-ASSY � �

09240-26600-71 Plug-in Analyzer � �



Section 1.3.4

4-44-4

SERVICE STANDARDSFILTERTightening Torque T=N·m (kgf·cm) [ft·lbf]Cover set bolt 6.4 to 7.8 (65 to 80) [4.7 to 5.8]Element tightening nut 1.0 to 1.2 (100 to 150) [0.7 to 1.1]REGULATORProtrusron of the idle adjust screw(Distance from the body face to the screw tip) 11.8 to 15.0 (120 to 150) [8.7 to 11.0]

Mounting height of the first spring adjuster mm (in) 13.9 (0.5)Pressure in the first reducing chamber kPa (kgf/cm2) [psi] 24.5 to 34.3 (0.25 to 0.35) [3.6 to 5.0]First valve lever height(From first cover contact surface) mm (in) 11.8 to 12.3 (0.47 to 0.48)

Second valve lever height(From second cover contact surface) mm (in) 0 to 2.0 (0 to 0.08)

Tightening Torque T=N·m (kgf·cm) [ft·lbf]Regulator first cover set screw 3.5 to 4.4 (36 to 45) [2.6 to 3.5]First valve set screw 3.5 to 4.4 (36 to 45) [2.6 to 3.5]First spring adjuster lock nut 3.5 to 4.4 (36 to 45) [2.6 to 3.5]Regulator second cover set screw 3.5 to 4.4 (36 to 45) [2.6 to 3.5]Second valve set screw 3.5 to 4.4 (36 to 45) [2.6 to 3.5]Slow solenoid valve set screw 3.5 to 4.4 (36 to 45) [2.6 to 3.5]Intake union 3.5 to 4.4 (36 to 45) [2.6 to 3.5]



Section 1.3.4

4-5

WIR

ING

DIA

GR

AM

SERVICE INFORMATION BULLETIN Subject: 8-Series LPG Regulators Page 1 of 1 MODEL APPLICATION: 8FGU15-32 and 8FGCU15-32 LPG and Dual Fuel GENERAL INFORMATION: Service Parts have been made available for improvement to 1st Valve durability where failures are related to Amine that is contained in LP fuel. It has been determined that Amine may be mixed in the LP fuel that is distributed to certain areas of the country. An Amine resistant valve has been added to service parts for cases where Amine may be added to the fuel. The updated 1st Valve and Overhaul kit uses a material based from Nitrile Butyl Rubber which is resistant to damage from the Amine that may be in the LP fuel.

REPAIR INFORMATION: When damage to the 1st Valve is found, especially after very low hours of operation, use the service parts listed below to repair the LP Regulator. PARTS INFORMATION:

Part Number Parts Name Model 23502-U2230-71* First Valve SUB-ASSY 8FGU15-32 and 8FGCU15-32 04221-U2050-71 First Valve Overhaul Kit 8FGU15-32 and 8FGCU15-32 23540-U1250-71 Regulator Assembly 8FGCU15-18 Only 23540-U2230-71 Regulator Assembly 8FGU15-32 and 8FGCU20-32

*Note – Part number 23502-U2230-71 is included in kit p/n 04221-U2050-71.

Fuel System FS08-001 September 15, 2008 8-Series LPG Regulators 8FGU15-32 (LPG and Dual Fuel) 8FGCU15-32 (LPG and Dual Fuel)

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