0302 delphi crdi final

DELPHI CRDi Fuel System

1MIAMI TRAINING CENTER

DELPHI CRDi Fuel SystemParts 1: General

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• COMMON RAIL BY LUCAS VARITY CONCEPT•• With the COMMON RAIL BY LUCAS VARITY system, the generation and • the control of high pressure are independent of the injection control.•• Therefore, the selection of the injection parameters (injection pressure, • number of injections, position of the injection and quantity for each • injection) can be freely selected for each operating point within limits • defined by the component sizing.•• Injection parameters, rail pressure and other engine parameters are • controlled by the Electronic Control Unit (ECM).

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FEEDING CIRCUIT

A low pressure circuit which feeds the fuel equipment with pressurised and filtered fuel.

HP CIRCUITA high pressure circuit with an HP pump to compress the fuel from the low pressure circuit to the rail through a high pressure pipe.

A rail to accumulate highly pressurised fuel, connected to the injectors by high pressure pipes.

Electronically controlled injectors (one per cylinder) which ensure the introduction of the required amount of fuel at the right time in the cylinders.

BACK-LEAK LP CIRCUITA back-leak low pressure circuit which has two main functions :

- to collect the pump back-leak flow and to divert it back to the tank- to collect the injector back-leak flow. This function is helped by a

venturi to create a vacuum in the back-leak pipe.5


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INLET MEETERING VALVE (IMV)

FUEL TEMPERATURE SENSOR

VENTURI(For return)

OUTLET (To C/rail)

INLET (suction)(From filter)


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• The functions of the HP pump are :• To generate the required high pressure level in the HP accumulator (rail), • To meter the compressed fuel quantity accurately according to the • power requirements of the engine in order to fulfill the high• pressure and fuel demands calculated by the ECM for a given• driver demand.

• The Common Rail pump consists of the following main elements :• The hydraulic head• The temperature sensor• The inlet metering valve• The high pressure outlet• The inlet valve• The outlet valve• The plungers• The roller / shoe assemblies• The drive shaft• The lift pump


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• The HP pump is made of two main parts :• Transfer pump• >> Blade concept Integrated to the HP pump • >> Pressure regulated to 6 Bar • >> Pump capacity : 5,6 cc/rev• >> Fuel flow : 90 l/h at 300 prpm and 650 l/h at 2500 rpm • >> Suction ability : 65 mBar at 100 prpm

• High pressure pump• >> Cam ring with 4 lobes • >> 2 chambers of 0,9 cc/rev (2 radial plungers by chamber) • >> Chambers phased at 45°• >> High pressure modulated by Inlet Meetering Valve• >> HP limitor (from 1800 to 2100 Bar)• >> Belt drive with speed ratio at 0.5


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1 Inlet Metering Valve(IMV)

2 Hydraulic Head3 Plunger

4Drive Shaft +Cam Ring

5 Housing6 Roller + Shoe

7 Transfer Pressure Pump

8 Temperature Sensor

9 Venting

10 Outlet High Pressure Flange

11 Transfer Pressure Regulator

High presser pump

High Pressure Pump Assembly


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High Pressure Pump Fuel FlowNormal operation (make a pressure)

High pressure pump is self lubricated from incoming fuel.


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High Pressure Pump Fuel FlowDeceleration (with out pressure)


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High Pressure Pump Fuel Flow

Filtered fuel is sucked through the HP pump inlet nipple. The fuel then passes into the transfer pump which raises the inlet pressure to a level known as transfer pressure. Natural transfer pressure is a function of pump speed.A regulator valve which forms part of the housing maintains this pressure at a pre-determined level (around 0.6 Bar). Fuel at transfer pressure also passes into the inlet metering valve which controls the amount of fuel delivered to the pumping element(s).The fuel enters the hydraulic head, is compressed by the plungers and forwarded to the high pressure pipe and then to the rail.

Pressures:Pump suction from tank: -100 mbarLow pressure : 6 bar (internal)High pressure: 1400 barBack leak (return): -0.5 bar

Transfer(Feed) Pump of High Pressure Pump

Transfer Pressure Regulator

INOUT


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Transfer (Feed) Pressure Regulator

OPERATING PRICIPLE

A regulating valve allows the transfer pressure to be maintained at a practically constant level ( about 6 bar) throughout the whole range of engines operations by returning some of the fuel to the pump inlet.

Regulating valve

High Pressure Plunger of High Pressure Pump


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IMV ( Inlet Metering Valve)The LP (Low Pressure) actuator also know as the IMV (inlet metering valve), is used

to control the rail pressure by regulating the amount of fuel which is sent to the

pumping element of the HP pump. in such a way that the pressure measured by the

HP rail sensor is equal to the pressure demand sent out by the ECU. of operation it

This actuator has two purposes. Firstly it allows the efficiency of the injection system

to be improved, since the HP pump only compresses the amount of fuel necessary

to maitain in the rail the level of pressure required by the system as a function of the

engines operating conditions.


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IMV ( Inlet Metering Valve)

The IMV is normally open when it is not being supplied with current. It cannot

therefore be used as a safety device to shut down the engine if required.

The IMV is controlled by current. The flow/current law is shown below.


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Common Rail (Linear Rail)

Rail - Empty mass :1.9kg- Volum :18cc- Bursting pressure : >7000 bar

RAIL DESIGN

The high pressure volume forwarded from the HP pump through a HP pipe isstored in the accumulator also named the rail. It consists of a distributor manifoldwhich provides the fuel at the injection pressure to the injectors through HP pipesand damps the pressure fluctuations.


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• The accumulator volume is defined in order to achieve :•• Pressure fluctuations as small as possible. The pressure fluctuations are due to• the pulsating supply of the fuel coming from the HP pump and to the fuel• consumed through the injectors. The target is to achieve rail pressure feedback at• rail pressure demand +- 15 bar in order to have a good accuracy of the injected• fuel quantity. A larger volume provides a better damping of the pressure• fluctuations.• Good startability. A smaller volume shortens the build up time and therefore allows• a quicker start.•• The rail volume is then a compromise between a large volume to reduce pressure• fluctuations and a small volume to achieve good startability.


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Common Rail (Pressure Sensor)Pressure sensor

>> Type : diaphragm/Piezo sensor >> Power supply : 5 +/- 0.25V>> Pressure sensing range : 0 to 1800

Bar>> Maximum pressure : 2200 Bar>> Burst pressure : over 2500 Bar

5V4.8V

4.5V

0.5V

0 1800 bar


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Common Rail (Pressure Sensor)

Supply 5V

Signal 0.5~4.5V

Ground 0V

5V4.8V

4.5V

0.5V

0 1800 bar


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Injector

TechnologyThe maximum injector pressures are approximately 1600 bar. the forces to be overcome in order to lift the needle of the injector are very large. Because of this, it is impossible to directly control the injector by using an electromagnetic actuator, unless very high currents are used, which would be incompatible with the reaction times required for the mulitple injections.


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Injector

This requires bulky and expensive power electronics and lead to considerable heating of the actuator and DCU. The injector is indirectly controlled by means of a valve controlling the pressurising or discharging of the control chamber located above the Needle:When the needle is required to lift (at start of injection), the valve is opened in order to discharge the control chamber into the return line. When the needle has to close (at the end of injection) the valve closes again so that the pressure is re-established in the control chamber.


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Injector

The purpose of the injector is to inject the required amount of fuel at the right time with variation of injection volume and start of injection as small as possible between engine cylinders.


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Injector

main injection

pilot 1 pilot 2 post pilot

• Quantity : 4• Injectors retained by clamping Opening by control valve solenoid• Multiple injections : Pilots, Main and Post• Drive pulse : In two parts (pull current and hold current) • Individual injector correction.• Variable injections pressure up to 1600 bars low • fuel delivery control up to 1600 bars • 100µs minimum between injections


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Injector assambly


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Injector (The Valve)In order to garantee response time and minimum energy consumption:

• The valve must be a light as possible

• The valve stroke must be as short as possible

The effort needed to move the valve must be minimal, which means that the valve

must be in hydraulic equalibrium in the closed position. Spring pressure ensures

contact between the valve and its Seat. To lift the valve, it is therefore required to

overcome the force applied by this spring.


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Injector (The spacer)The spacer is situated underneath the valve support. It intergrates the control

chamber and the three calibrated orifices which allow operation of the injector. The

orifices are:

• The injector supply orifice (Nozzle Path Orifice: NPO)

• The control chamber discharge orifice (Spill Orifice: SPO)

• The control chasmber filling orifice (Inlet Orifice Control: INO)


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INJECTOR

Adaptor plateControl valve


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Injector Operation No current is sent to the control valve solenoid, the control valve is closed, the pressure in the control chamber is the same as in the rail, the nozzle is kept closed.

The control valve solenoid is energized via the ECM, the control valve lifts, the fuel pressure in the needle control chamber starts to drop, the nozzle is still closed. When the pressure in the control chamber has dropped sufficiently and as the fuel pressure at the nozzle seat remains equal to the rail pressure, the nozzle needle is unbalanced and moves upwards.


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Injector Operation (Phase 1)


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Injector Operation (Phase 2)


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Injector Operation (Injection)Electromagnet field


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Injector Operation (End of Injection)

The ECM cuts the current to the control valve solenoid, the control valve returns to its seat due to the solenoid spring force, the pressure in the needle control chamber increases and becomes "slightly" larger than the pressure in the nozzle seat thus closing the needle and stopping the injection.


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Injector Operation (Injection)


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Injector Operation Injector Control

The control current of the injector coil has the following form:

Pull peak=24.5 A nomHold peak=6.8.A nomPull trough=7.4.A nomHold trough=5.2.A nom

The low current allows for the Joule effect losses in the DCU and injector to be reduced. The call current is higher than the hold current because during the hold phase:

-The air gap between the valve and the coil is reduced (by the valve stroke value i.e. about 30 µm and the electromagnetic force to be applied to the valve can thus be reduced.

-It is no longer necassary to overcome the valves inertia


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Injector Operation

Discharge through the injectors

When the rail pressure demand suddenly drops:

- Foot off the accelerator (overrun)

- Or durinig a fault requiring the rapid discarge of the rail

Closing the IMV will not allow the new required pressure defined by the DCU

to be reached quickly enough. The system therefore usues the injectors to

discharge the rail.This method is based upon the response time of the

injectors. In fact, to discharge the HP circuit without risking the introduction of

fuel into the cylinders, it is necessary to supply the coils with pulses which

are long enough to lift the valve and thus bring the rail into direct

communiccation with the injectors return circuit, but short enough to prevent

the injector needle from lifting and thus causing the unwanted introduction of

fuel into the combustion chamber.


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Injector Operation Discharge through the injectors (cont)

This method of operation is only possible if the control of the response time

of the injector is perfect, i.e. the time between the start of energizing of the

solenoid valve and the moment at which the injector needle lifts.

This time is obviously different for each injector because it depends on initial

characteristics and amount of wear of the injector. It is therefore essential to

accurately know the initail characteristics and deviation of each injector.

The injectors of the common rail system are very high precision parts.They are

capabel of injecting flows ranging from 0.5 to 100 mg/stroke at pressures of 150 to

1600 bar. Extremely high production tolerances are required. However, due to slight

variations in maching, pressure drops, mechanical friction, and magnetic force may

vary between Injectors, as a result deviations up to 5 mg/stroke can occur.

This means it is impossible to effectively control an engine with such differences

between the injectors. It is therefore necessary to apply a correction which will make

it possible to inject the required amount of fuel whatever the initial characteristic of

the injector, to do this , it is necessary to know the this characteristic and to correct

the pulse applied to the injector according to the differences between this

charcteristic and the Target stored in the DCU.


Injector Individual Calibration

All injectors are numbered into a batch depending upon there particular

characteristic, by using a data matrix code (for production line) and a alphanumerical

code (for aftersales service)

- If an injector is replaced it is necessary to load the value into DCU

- If all injectors are replaced, ALL values must be loaded into DCU

- To reset the learnt perameters which characterise the state in which the system has programmed itself. Because the system is starting again with new components, it is advisable to return these programmings to the original values.

If a DCU is replaced, it is then necessary to:

- Load ALL the values and the vehichle configuration into the new DCU

- To copy the learnt parameters which charcterise the state in which the system is in. As the DCU is new it will not know these values, it will therefore use neutral values. To ensure optimum operation from the first start it is necessary to record these values in the DCU.

Re-programming is explained further in the Hi-Scan section.

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CII for A/S

CII for production


Further details on calibration can be found in the

Hi Scan section

Injector tightening Torque P1 Injector :19m.N +/- 5


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• Environmentally friendly,throw-away filter, Periodicity : 60.000Km • Quick-fit connections Inlet,outlet, & Return• Equipments : Water drain screw (every 20 000Km recommended• Reheating : gasoil recirculation

Fuel FilterFiltration:

85% of 5µ particles

97% of 10µ particles


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Fuel Filter (Recirculation)The filter has an internal bi-metal strip, in cold conditions the fuel return from the HP pump is directed through the filter housing, to be mixed with new fuel going into the HP pump.As a result of friction and compression in the HP pump the leak fuel temperature is rapidly increased. This sysem is acting as a fuel heater.When the fuel temperature has reached approximately 40°C the bi-metal strip releases the steel ball closing the port, allowing the return fuel to flow to the fuel tank.


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Fuel Filter (Recirculation)

To Pump

From Pump

To Pump

From Pump

To Tank

Cold

Hot

Bi-metal stripSteel ball


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Fuel heater Fuel

filter

Primingpump

Fuel Filter (Recirculation)

Fuel heater is operated by bi-metal which is located inside of fuel heater. Bi-metal is closed(switch “on”) when the temperature reaches below -2°C. Bi-metal is opened(switch “off”) over 3 °C.

Specification of fuel heater- Operation voltage :

battery voltage- Maximum voltage : 24V- Current : 11A- Sealing pressure : 6bars- Sealing vacuum pressure :

0.5bar- Life : 10000cycles


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• The requirements for the Common Rail System protection are :• - High retention capacity especially towards fine particles, • required to meet ISO 14/8 cleanliness level, • - Sensing, separation and collection and sensing of water from the Diesel

(critical for some markets e.g India, Eastern Europe...)• - Fuel de-waxing :• - Electrical heater (Option,Not on Terracan)• - Fuel re-circulation (Available)• - Air management (air splitting system)• - Other requirements :• - Maximum fuel flow through the filter : 120 l/h.• - Compact design.• - Extended filter life.• - Material recycling / recovery.


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• ECM hardware : C2 level• ECM software : C7E

Microcontroller : Siemens C167CS with an external flash memory Conectors : 3 module mouled as part of plastic case, (112 pins),

1x48 pins and 2x32 pins Normal operating voltage : between 8V and 16VDiagnostic : Protocol Keyword 2000 by K line Specific functions :

>> Smartra anti-theft>> Air heater resistors

Other functions :>> EGR control>> Water heater control

>> Air conditioning control>> Engine cooling control

ECM


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AFSAccelerator pedal sensorCMP sensorCKP sensorRail Pressure sensorKnock sensor(Accelerometer)Fuel Temperature sensorECT sensorIAT sensorVehicle Speed sensorBrake switchClutch switch(M/T)A/C switchA/C Pressure sensor

ECM

Main RelayInjectorCooling Fan controlAir HeaterEGR ValveMIL lampInlet Metering Valve

ECM


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Exhaust Gas Return (EGR)EGR OFF Condition

•Coolant temp under 15°C

Or over 100 °C

•Intake air temp over 60 °C

•Engine RPM over 2500rpm

•Engine load over 40% of Max.

•A/C on

•Altitude over 1000 Meters

•Air flow sensor fault

•During cranking (and for 2 secs)

ECU is controlling a solenoid valve to apply a

vaccum to operate the EGR. Feed back control

is via the air mass sensor HFM5

EGR Valve

Solenoid Valve


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Heat ExchangerHeat exchanger

The heat exchanger, located at the

rear of the cylinder head, is to cool the

EGR gases entering the intake manifold.

Cabin Heater

The Terracan is not fitted with a cabin

Heater for the following reasons:

-Engine capacity is larger than that of

the `D` engine.

-Heater inlet hose diameter has been

increased.

The above meets the target requirements of cabin warm up.Heat exchanger


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Air Intake Heater

Engine_cycle_speed

Fuel_demand

Vbat

Coolant_temperature

ECU

IG1

BAT

RELA

Y2

RELA

Y1

A/H

EATER

2

A/H

EATER

1

GND

DIAG1

DIAG2

AIH_relays_drive

A/HEATERLAMP

Atmospheric_pressure

Air Intake heater

Intake heater manifold

Mainly the ECU is monitoring the coolant

temperature, should the temperature

be in the operating range the air intake

heating element/s are operated for the

duration as listed in the following chart

Specification:Vbatt: 14VResistance: 0.2 ΩCurrent: 70 A ( x two elements = 140 Amps


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The air intake heating element is controlled by the ECU, which must consider

many variables as listed below:

Atmospheric_pressure

Battery_voltage

Coolant_temperature

Checked_main_fuel_demand

Engine_speed

Engine_stop_request

AIH_Diag_high2

AIH_Control_ISO_request

Coolant_temp_faults

AIH_Diag_high1

ISO_AIH_Lamp_active

AIH_Relay_faults

AIH_Lamp_drive_mode

AIH_Relay_drive_mode

Air heaters

Preheat_entry_timeECM


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Air Intake Heater (Pre & post Heating)

Temp °C Time (sec)

-30 26 sec

-25 20sec

-20 15sec

-15 10sec

-10 5.5sec

-5 3.5sec

0 2sec

+20 0sec

Temp °C Time (sec)-20 26 sec-10 20sec0 15sec

+20 10sec+80 5.5sec

Pre-Heating Post-Heating

During the post heating time, Air heating elements are switched on, alternating

between circuits 1 & 2 for 10 secs.

In addition, after starting the engine RPM did not reach 3000rpm the heater elements are continued to be powered for a maximum of 180 secs.

Air Flow Sensor

Air Flow Sensor

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Air flow Sensor


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Safety Instructions•It is strictly prohibited to smoke or to eat while working on the Common Rail injection system.

•It is essential to disconnect the battery before any work is done on the Common Rail injection system.

•It is strictly forbidden to work on the Common Rail injection system with the engine running.

•It is necessary to read the value of the rail pressure and of the diesel oil temperature with the engine running.

•It is necessary to read the value of the rail pressure and of the diesel oil temperature with the aid of the diagnostic tool before any work is done on the fuel circuit. The opening of the circuit can only begin if the diesel oil temperature is less than 50°C (122°F) and the rail pressure is close to 0 bar. If it is not possible to communicate with the computer, wait for 5 minutes after the engine has stopped before starting any work on the fuel circuit.


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Safety InstructionsIt is strictly prohibited to supply an actuator directly off an external power supply.

The injector must not be dismantled.

The HP sensor must not be removed from the rail. If the HP sensor fails, It is essential to replace the complete rail.

The IMV, the diesel temperature sensor and the venturi must not be removed from the pump. If one of these components is faulty, the whole pump must be replaced.

The HP pipes are not reusable : a removed pipe must be replaced.

Decarbonizing the injector in an ultrasonic bath is strictly prohibited.The computer’s metal casing must never be used as an earth!

During welding jobs (bodywork repairs), the ECM must be carried out byqualified staff who have received training at the DELPHI DIESEL SYSTEMS training center.


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General cleanliness instructions• STORAGE OF PARTS

• Environmental conditions• -30℃ to + 60℃(-22℉ + 140℉).• Humidity of 0 to 80%.•• Magnetic environments• The injector holder must not be left close to a magnetic field source at a level higher than 400A/m.•• Packaging• Each of the system components must be packed be packed in a sealed plastic pouch. The holes must

be protected with suitable plugs.


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• The packaging of the spare parts should be opened just before they are used. Moreover, the sealing plugs must not be removed until the final connection is made. The plugs and the sealed pouches must be discarded after use.

•• Any part which has been dropped must be returned to DELPHI DIESEL SYSTEMS for

assessment.• Before fitting the injector, is it essential to ensure that its socket is clean.


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High Pressure Plunger of High Pressure Pump

High Pressure Pipes

1. 4 HP pipes rail / injector

2. 1 HP pipe pump / rail

If the Injector or main rail feed pipes are removed they MUST BE REPLACED WITH NEW

During the removal of the injection system

When the injection system has been opened, it is strictly prohibited to use a blower, a brush or a tube brush, since these tools might cause impurities to get into the system.As soon as an orifice has been opened, it is essential to block it using the appropriate plug.

* WARING THE PLUGS MUST BE DISCARDED AFTER USE.

After opening up and blocking the holes, each component of the injection system must be stored in a new sealed pouch.

Cleaning of the injector is strictly forbidden, even with an ultrasonic cleaner. Moreover, the separation of the injector from the injector holder is prohibited.

During reassembly of the injection system

The packaging of the spare parts should be opened just before they are used. Moreover, the sealing plugs must not be removed until the final connection is made. The plugs and the sealed pouches must be discarded after use.

Any part which has been dropped must be returned to DELPHI DIESEL SYSTEMS for assessment.Before fitting the injector, is it essential to ensure that its socket is clean.

Delphi Common Rail Cap Kit

Delphi Common Rail ECU & HP Pump

Delphi Common Rail F/Filter & Injector

Removal a rail/injector pipe(rail/HP pump)1. Clean the nuts of the HP unions with a

solvent (CARCLEAN type) applied with a clean brush(Figure3).

2. Vacuum the particles with the aid of a ‘BLOVAC BV11’ type suction device(Figure4).

3. Disconnect the injector with the aid of pliers, applying pressure to the locking clips on the side of the connector.

Removal a rail/injector pipe (rail/HP pump)4.. Slacken the nut screwed onto the

injector using a 17 mm(0.67 in) open wrench(Figure4)

5. Slacken the nut screwed onto the rail using a 17 mm(0.67 in) open wrench(Figure 5).

* NoticeIt is important to positions the wrench level with the solid end of the nut, in order to apply the stresses to the strongest part of the nut. If the torque is applied to the open end of the nut,. There is a risk of distortion of the nut when it is tightened. Or use a pipe-wrench with cloth.

Removal a rail/injector pipe (rail/HP pump)6. Move the nut along the pipe, keeping

the olive in contract with the injector cone(Figure 6) and vacuum the particles in the contact area between the olive and the cone, using a pneumatic suction device.

7. Carry out the same operation on the rail side.

8. Remove the pipe and vacuum the particles inside the injector cone with the aid of the pneumatic suction device (Figure 7).

Assembly a rail/injector pipe (rail/HP pump)


Clean pipe- Must be clean before install the pipe.

1. Incase of damaged the High presser Pump.

- Replace common rail kit for the new one.

or remove and clean common rail and all the pipe.

2. Incase of change injector or maintenance

system.

* Self cleaning

- Install the pipe on rail and tithing the pipe olive

and open other side pipe to container

(Do not install other side pipe, just remain out side)

- Cranking the Engine for blow out the inside of pipe

using fuel from High presser pump.


3. Fit the pipe olive into the injector cone and the rail cone. Tighten the nut by hand (Figure 10).

Assembly a rail/injector pipe (rail/HP pump)4. Tighten the nut on the injector side to 40 Nm(29.5 lb-ft), applying reverse torque with the support tool for the injector holder (Figure 12).

* NoticeWhen tightening the nut, ensure that the connector remains aligned with the injector row axis (Figure 13).

5. Tighten the nut on the rail side to a torque of 40 Nm(29.5 lb-ft)

ESSNTIALTo validate the repair, start the

engine an check the tightness of the HP connection.

Injector holder-removal1. Remove the HP pipe of the injector being removed (following the method indicated in refer to page).

2. Disconnect the injector connector

3. Disconnect the injector leakage return hose(Figure2).

4. Slacken off the flange of the injector holder(Figure3).

5. Remove the injector with the flange and its bolts.

Assembly of injector holder1. Clean the socket of the injector holder and

vacuum the particles using the pneumatic suction device(Figure 5).

2. Clean the flange of the injector holder with solvent (CARCLEAN type) using a clean brush.

3. Place a new heat protection washer on the seat of the injector holder.* WARNINGIT IS PROHIBITED TO RE-USE AN OLD HEAT PROTECTION WASHER!

4. Fit the injector holder with its flange.

5. Tighten the injector holder flange bolt to a torque of 19 Nm(14.01 lb-ft)(Figure 6).

6. Reconnect the return hose of the injector holder. Reconnect the injector connector.

7. Reassembly the HP pipe, referring to the method described in page.

0302 delphi crdi final

Documents

rail pressure

hp pump pressure

high pressure outlet

pressurehigh pressure

control of high pressure

high pressure pipes

pressurised fuel

filtered fuel