general ignition system service -...

177

PART 9-2DUAL ADVANCE DISTRIBUTORS . . . . 9-22

9-1

PART91

GENERAL IGNITION SYSTEM SERVICE

Section Page Section Page1 Diagnosis andTesting 9-1 3 Cleaning and Inspection 9-212 CommonAdjustmentsandRepairs 9-17

CONVENTIONAL IGNITIONSYSTEM

The ignition system consists of aprimary low voltage anda secondary high voltage circuit Fig. 1.

The primary circuit consists ofthe:

1. Battery.2. Ignition switch.3. Primary circuit resistancewire.4. Primary windings of the igni

tion coil.5. Breaker points.6. Condenser.The secondarycircuit consistsof

the:1. Secondarywindings of the igni

tion coil.2. Distributor rotor.3. Distributor cap.4. High tension wires.5. Sparkplugs.When the breaker points are

closed, the primary or low voltagecurrent flows from the batterythrough the ignition switch to theprimary windings in the coil, thento groundthroughthe closedbreakerpoints. When the breaker pointsopen, the magneticfield built up inthe primary windings of the coilmoves through the secondarywindings of the coil producing high voltage current. High voltage currentis producedeach time the breakerpoints open. The high voltage flowsthrough the coil high tension lead to

the distributor cap where the rotordistributesit to oneof the sparkplugterminals in the distributorcap.Thisprocessis repeatedfor every powerstrokeof the engine.

TRANSISTOR IGNITIONSYSTEM

The permatuned transistor ignitiori system is available on the 430V-8 engine. Figure 2 shows a schematic of the transistor ignition systern.

The ignition coil primary in the

transistorsystemis designedto draw12 amperespeakcurrent, or approximately 5.5 amperesaveragecurrent,as indicatedon an ammeter,in orderto provide high spark plug voltageat the higher enginespeeds.

The transistor in the system actsas a heavy duty switch or relay. Itis similar in action to a horn relay,except that it has no moving parts,and thus acts with very little timelag. The transistoris connectedbetween the battery andthe coil, andis used to make and break the coil

GENERAL IGNITION SYSTEM SERVICE . . 9-1PART 9-1 PAGE PART 9-3 PAGE

SPECIFICATIONS 9-27

O DIAGNOSIS AND TESTINGGENERAL INFORMATION

FIG. 1 -Typical Ignition Circuit

GROUP 9-IGNITION SYSTEM

primary circuit.Thedistributorcontrolsthetransis

tor. The 8-ohm resistor, connectedbetweenthe distributorandthe transistor in the wiring harness,limitsthe transistor control current anddistributor point current to 0.5 ampere. The low distributor point current eliminatespitting andgiveslongdistributor point life.

The distributorcondenserhasbeenincreasedin value to 2 mfd, and islocatedin the amplifier assembly.Asin the standard ignition circuit, itabsorbshigh inductive energyduringinitial distributor point opening.However, it no longerhas anyeffecton the distributor points as the transistor effectively isolates the pointsfrom the coil.

The amplifier assemblyFig. 3 ismountedunderan insulatedcoveronthe left front fender inner panel.

A ceramic ballast resistor ismountedwith the amplifier, a tachometer connectorblock is mountedon the firewall anda cold start relayis mountedon the right, front fenderin the engine compartment.

A 2-amperefuse in the collectorto tachometerblock lead preventsthe transistor from being damaged

FIG. 3-Amplifier

by the applicationof externaldevicesother than normal testingequipment.

The cold start relay contacts arenormally closed and they are connected into the circuit only duringthe start cycle. When the starterrelay is closed,the cold startrelay isactuatedand opens its contacts. If,during starting, the available voltagedrops below 10.5 volts, the relaycontacts close, thus by-passing the0.33-ohm resistor in the ballast resistor block, and applying full available voltage to the system.

The tachometerblock is used to

connecta tachometeror other testequipmentinto the circuit. Do notconnect test equipment into thecircuit in any other manner, orreadings will be inaccurate anddamage may occur to the transistor, or change its operating characteristics.

Connectthe tachometerred leadto the tachometerblock red terminalandblacklead to the blackterminal.

TROUBLE ISOLATION

CONVENTIONAL IGNITIONSYSTEM

Ignition systemtroublesarecausedby a failure in the primary/or thesecondarycircuit or incorrect ignition timing. If an engine troublehasbeentracedto the ignition systern from the"Engine TroubleDiagnosis Guide", the trouble can befound by performingan ignition system test on a scope or by wtherisolating the trouble to the primaryor secondarycircuit as follows:

1. Remove the coil high tensionleadfrom the distributor cap.

2. Hold the high tension lead approximately Yi; inch from the cylinder head.

9-2 178

FIG. 2-Transistor Ignition System Schematic

B1717-C

81844-B

Assembly

PART 9-1 -GENERAL IGNITION SYSTEM SERVICE 9-3

3. With the ignition switch on,crank the engine and check for aspark.

If the spark is good, the troublelies in the secondarycircuit.

If there is no spark or a weakspark, the trouble is in the primarycircuit, coil to distributor high tension leador the coil.

PrimaryCircuit. A breakdownorenergy loss in the primary circuitcanbe causedby:

1. Defective primary wiring.2. Burned or improperly adjusted

breakerpoints.3. A defectivecoil.4. A defectivecondenser.

SecondaryCircuit. A breakdownor energy loss in the secondarycircuit can be causedby:

1. Fouled or improperly adjustedsparkplugs.

2. Defective high tension wiring.3. High tensionleakageacrossthe

coil, distributor cap or rotor.

TRANSISTOR IGNITIONSYSTEM

Do not use any testing procedures or conventional short cutsother than those listed below, orextensivedamagecan result to thesystem.

Ignition troubles are causedby afailure in the primary or secondarycircuit, or incorrect ignition timing.Isolate the trouble as follows:

1. Remove the coil high tensionlead from the distributor cap.

2. Hold the high tension leadapproximately ¼ inch from thecylinder heador good ground.

3. With the ignition switch on,crank the engine and check for aspark. The engine may be crankedby the conventionalmethod of running a jumper wire from the batterypositive terminal to the "S" terminalof the starter relay, after disconnecting the red and blue lead atthe relay.

If the spark is good, the troublelies in the secondaryhigh voltagecircuit. If there is no spark or aweak spark, the trouble is in theprimary low voltage circuit.

Primary Circuit. A breakdownot energyloss in the primary circuitcan be causedby:

1. Defectiveprimary wiring.2. Improperly adjusted, contami

natedor defectivedistributor points.3. Defectiveamplifier assembly.SecondaryCircuit. A breakdown

or energyloss in the secondarycircuit can be causedby:

1. Fouled or improperly adjustedspark plugs.

2. Defectivehigh voltagewiring.3. High voltageleakageacrossthe

coil, distributor cap or rotor.

PRIMARY CIRCUIT TESTS

CONVENTIONALIGNITION SYSTEM

A complete test of the primarycircuit consists of checking the circuit from the batteryto the coil, thecircuit from the coil to ground,andthe starting ignition circuit.

Excessive voltage drop in theprimary circuit will reducethe secondary output of the ignition coil,resulting in hard starting and poorperformance.

Battery to Coil Test

PROCEDURE

1. Connectthe voltmeter leads asshown in Figs. 4 and 5.

2. Install a jumper wire from thedistributor terminal of the coil toa good ground on the distributorhousing.

3. Turn the lights and accessoriesoff.

4. Turn the ignition switch on.

RESULTS. If the voltmeter reading is 6.9 volts or less, the primarycircuit from the battery to the coilis satisfactory.

FIG. 4-Battery to CoilTest- Rotunda Tester

179

Sun

82001-A

FIG. 5-Battery to CoilTest-Sun Tester

If the voltmeterreadingis greaterthan 6.9 volts, check the following:

1. The batteryandcablesfor looseconnectionsor corrosion.

2. The primary wiring for worninsulation,brokenstrands,and looseor corroded terminals.

3. The resistancewire for defects.4. The relay to ignition switch for

defects.

Ignition Switch Test

PROCEDURE


2. Install a jumper wire from thedistributor terminal of the coil to agood groundon the distributor body.

3. Turn all of the accessoriesandlights off.


RESULTS. If the voltmeterreading is 0.3 volt or less, the ignitionswitch andthe relay to switch wireare satisfactory.

If the voltmeter readingis greaterthan 0.3 volt, either the ignitionswitch and/orthewire aredefective.

Resistance Wire Test

PROCEDURE


82000A 2. Install a jumper wire from thedistributor terminal of the coil to agood groundon the distributorhousing.

9-4 GROUP 9-IGNITION SYSTEM 180

ITB2002-A

FIG. 6-ignition Switch FIG. 8-Resistance Wire FIG. lO-Starting IgnitionTest -Rotunda Tester Test -Rotunda Tester Circa it Test-Rotun do Tester

3. Turn all of the accessoriesandlights off.


RESULTS. If the voltmeterreading is 6.6 volts or less, the resistancewire is satisfactory.

If the voltmeter readingis greaterthan 6.6 volts, replacethe resistancewire.

FIG. i-Ignition SwitchTest-Sun Tester

Starting Ignition Circuit Test

PROCEDURE

1. Connect the voltmeter leads asshown in Figs. 10 and 11.

2. Disconnectand groundthe coilto distributorhigh tensionleadat thedistributor.

3. With the ignition switch off,crank the engine by jumping the

ignition switch at the solenoid whileobservingthe voltage drop.

RESULTS. If the voltage dropis 0.1 volt or less, the starting ignition circuit is satisfactory.

If the voltage drop is greaterthan0.1 volt, clean andtighten the terminals in the circuit or replace thewiring as necessary.

FIG. li-Starting IgnitionCircuit Test-Sun Tester

Red.

+

82004-A 82006-A

Sun

Black

B2003-A 82005-A

FIG. 9-Resistance WireTest-Sun Tester

B2007-A

PART 9-i -GENERAL IGNITION SYSTEM SERVICE 9-5

Coil to Ground Test

PROCEDURE


2. Close the breakerpoints.3. Turn all lights and accessories

off.4. Turn the ignition switch on.

RESULTS. If the voltmeterread-

FIG. 12-Coil to GroundTest-Rotunda Tester

FIG. 13-coI to GroundTest-Sun Tester

ing is 0.1 volt or less, the primarycircuit from coil to ground is satisfactory.

If the voltmeterreadingis greaterthan 0.1 volt, test the voltage dropof each of the following:

I. Coil to distributor primarywire.

CONDITION CAUSED BY

Any discolorationother thana frostedslategrey shall be consideredasburnedpoints.

EXCESSIVE METALTRANSFER OR PITTING

Incorrect alignment.Incorrect voltage regulator setting.Radio condenserinstalled to thedistributor

side of the coil.Ignition condenserof improper capacity.Extendedoperationof the engineat speeds

other thannormal.81443-B

FIG. 14-Breaker Point InspectionNO SPARK AT COIL

WITH IGNITION ON AND COLD START RELAY DISCONNECTED,CONNECT DWELL METER TO TACH BLOCK AND CRANK ENGINE

0° DWELL 0° TO 45° DWELL 45° DWELL

1.

2.

POINTS ARE CONTAMINATED TROUBLE 1. NO POWER FROM IGNITIONOR ARE NOT CLOSING. I IS NOT IN SWITCH.OPEN CIRCUIT IN DISTRIBUTOR I TRANSISTOR 2. POINTS ARE NOT OPENING.LEAD TO AMPLIFIER. CIRCUIT 3. AMPLIFIER IS MALFUNCTIONING.

181

2. The movablebreakerpoint andthe breakerplate.

3. The breakerplate and the distributor housing.

4. The distributor housing, andengineground.

Breaker Points. The breaker

DISCONNECT DISTRIBUTOR LEAD AND CRANK ENGINE

0° DWELL

L POINTS ARE NOT OPENING

45° DWELL

1. NO POWER FROM IGNITION SWITCH.

L2 AMPLIFIER IS MALFUNCTIONiNG.

CONNECT DISTRIBUTOR LEAD. CONNECT VOLTMETERTO RED TERMINAL OF TACH BLOCKAND TO GROUND. CRANK ENGINE.

NO VOLTAGE

82009-A J NO POWER FROM IGNITION SWITCH J

STEADY VOLTAGE

AMPLIFIER IS MALFUNCTIONING J81890-A

FIG. l5-Transistor Ignition System Test Procedures

9-6 GROUP 9-IGNITION SYSTEM

point assemblyconsists of the stationary point bracket assembly,breaker arm and the primary wireterminal.

Breakerpointsshouldbeinspected,cleaned and adjusted as necessary.Breaker points can be cleaned withchloroform anda stiff bristle brush.Replacethe breakerpoint assembly

* if the contactsare badly burnedorexcessivemetal transferbetweenthepoints is evident Fig. 14. Metaltransferis consideredexcessivewhenit equalsor exceedsthe gap setting.

Coil. The coil should be testedfollowing the instructions under"Ignition SystemTests".

Condenser.The condensershouldalso be testedfollowing the instructions under "Ignition SystemTests".

TRANSISTORIGNITION SYSTEM

When diagnosisproceduresisolatetrouble to the primary circuit, makethe following tests to locatethe defective items. Do not use any otherprocedure, conventional short cut,or connect test equipment in anyother manner than that describedor extensivedamagecan be causedto the transistor ignition system.Figure 15 shows the transistorignition system tests in outline form.

Disconnectthe cold start relay.Connectadwell meterto thetachometer block. Connect the black leadto the black terminal and the redlead to the red terminal. Turn theignition on and crank the engine.Observethe dwell meter reading.

0° Dwell. A dwell reading of 0°indicates:

1. The distributor points are contaminated or are not closing.

0° to 45° Dwell. A dwell readingbetween0° and 45° indicates:

1. The transistor andthe primarycircuit are functioning properly.

2. The trouble could be in thesecondarycircuit.

45° Dwell. A dwell reading of45° indicates:

1. No power from the ignitionswitch.

2. The distributor points areclosed and not opening.

3. Defective amplifier assembly.To determinewhich of the three

items listed are causing the troubleproceed as follows:

Disconnectthe distributor lead atthe bullet connector,and crank theengine. If the dwell meter indicates0° dwell, the distributor points are

not opening. If 45° dwell is indicated,theamplifier is malfunctioningor there is no power from the ignition switch.

Use a voltmeter or test light todetermineif the transistoramplifierassembly is at fault. Connect thevoltmeterto thered-greenleadterminal of the ballast resistor and toground.Crankthe engine.

If a steady indication of voltageis obtained, the trouble is in theamplifier. Absence of any voltageindication on the voltmeter showsthere is an opencircuit, or no powerbetweenthe ignition switch and theamplifier. The ballast resistor couldbe defective.Replaceit with aknowngood ballast resistor,and repeatthetest.

If the test procedure indicates adefectiveamplifier, replaceit with aknown good amplifier, and proceedas follows:

Connect the distributor high tension lead at the bullet connector.Then, with the cold start relay disconnectedand the dwell meterconnected to the tachometer block,crank the engine and observetheindicateddwell. A readingbetween0° and 45° indicates satisfactoryignition; thus, the amplifier is atfault.

If the dwell reading is still 450,

thewiring from the amplifier throughthe ballast resistorto the coil is defective. Replacethe defective item.

SECONDARY CIRCUIT TESTS

The following procedure is usedon both ignition systems.

PRELIMINARY CHECKS

1. Removethe coil to distributorhigh tensionlead andthesparkplugwires from the distributor cap andfrom the spark plugs. Inspect theterminals for loosenessand corrosion. Inspect the wires for breaksand cracked insulation. Replace alldefectivewiring.

2. Cleanthe inside of the distributor cap, and inspect it for cracks,burned contacts,permanentcarbontracks or a defectivecenter carbonbrushelectrode.Removedirt or corrosion from the sockets.Replacethecap if it is defective.

3. Inspect the rotor for cracksordefects. Replace the rotor if it isdefective.

SECONDARY HIGH TENSIONWIRES

wires connectingthe distributor capto the sparkplugs and the wire connecting the center terminal of thedistributor cap to thecenterterminalof the ignition coil.

These wires are the radio resistance-typewhich filter out the highfrequency electrical impulses thatarethe sourceof ignition noiseinterference.The resistanceof each wireshould not exceed 24,500 ohms.When checking the resistanceofthewires for setting ignition timing, do not puncture the wireswith aprobe. The probe may causea separation in the conductor.

At regular intervals, clean andinspect the wires for crackedinsulation and loose terminals..Repair orreplace the wires as required. Asparkplug wire set is available forservice.

When removing the wires fromthe spark plugs,grasp the mouldedcap only. Do not pull on the wirebecausethe wire connection insidethe cap may become separatedorthe weather seal may be damaged.

Spark Intensity

1. Disconnect a spark plug wire.Check the spark intensity of onewire at a time.

2. Install a terminal adapter inthe terminal of the wire to bechecked. Hold the adapterapproximately j’iA inch from the exhaustmanifold andcranktheengine, usinga remotestarter switch. The sparkshould jump the gap regularly.

3. If the sparkintensity of all thewires is satisfactory, the coil, condenser, rotor, distributor cap andthe secondary wires are probablysatisfactory.

If the spark is good at only somewires, perform a high resistancetestof the faulty leads.

If the spark is equal at all wires,but weak or intermittent, make ahigh resistancecheck of the coil,distributor cap and the coil to distributor high tension wire. Followthe instructionsof thetest setmanufacturerwhen making the tests.

On the transistor ignition, donot test the coil on a coil tester,as inconclusiveresultswill be obtained due to the very low coilprimary inductance. Substitute aknown good coil and perform theprimary circuit tests.

SPARK PLUGS

182

The secondarywires include theClean, inspect and gap the plugs

following the instructionsin Sections

9-7PART 9-1--GENERAL IGNITION SYSTEM SERVICE

2 and3. After the propergap is obtained, checkthe plugs on a testingmachine.Comparethe sparkingefficiency of the cleanedand gappedplug with a new plug. Replacetheplug if it fails to meet 70% of thenew plug performance.

Test the plugs for compressionleakage at the insulator seal. Applya coating of oil to the shoulderofthe plug where the insulator projectsthrough the shell, andto the top ofthe plug, where thecenterelectrodeand terminal project from the insulator. Place the spark plug underpressurewith the tester’s high tension wire removed from the sparkplug. Leakage is indicated by airbubbling through the oil. If the testindicates compression leakage, replace the plug. If the plug is satisfactory, wipe it clean.

IGNITION TIMING

Incorrect ignition timing can becausedby:

1. Timing incorrectly adjusted.2. Distributor bushing and/ or

shaft worn, or a bent distributorshaft.

3. Defectivevacuum advancesystem.

4. Defectivecentrifugal advance.

IGNITION SYSTEM TESTS-ROTUNDA TESTERS

TEST CONNECTIONS-RE-235,RE-651, AND RE-881

The test connectionsfor the RE-235 testerareshown in Fig. 16, thetest connections for the RE-651teter are shown in Fig. 17, and thetest connections for the RE-881tester areshownin Fig. 18.

1. With the testerturned off, plugthe power plug into a proper ACoutlet.

2. Connect the green lead to thedistributor terminalof the coil.

On a car equipped with atransistor ignition, connect thisgreen lead to the terminal on thered side of the tachometer block.

3. Remove the No. 1 plug wirefrom the distributor cap, place theblue pickup in the cap andplacetheplug wire in the pickup.

4. Now connect the black lead toa good ground.

If the car has a transistor ignition, connectthe black leadto theterminal on the black side of thetachometerblock.

6. If the engine timing is to bechecked, plug the timing light intoits socket.

The following stepspertainto theRE-651 and RE-881 testersonly.

7. Disconnect the battery wirefrom the regulator and place it inthe knob end of the 100 ampereshunt.

8. Place the spade terminal fromthe 100 ampereshuntandthe yellowlead on the battery terminal of thevoltageregulator.

9. Turn thegroundpolarity switchto the minusposition. On theRE-881tester, turn the volts switch to the 20volt position.

POINT RESISTANCE TEST

RE-651 Tester

1. Remove and ground the hightension wire from the centerof the

distributor.2. Turn the volts switch to the

point resistance PT. RES. position. The points should be closedforthis test. If the breaker points areopen, the meterwill readthe batteryvoltage 0 to 40 scale.

3. "Bump" the starter with thestarter switch until the voltmeterpointer decreasesto the lowest reading in the black zone. On a carequipped with a transistor ignition, this bumping is done byjumping between the "5" terminalof the solenoid and the batterywith the ignition switch off andthe coil lead brown wire disconnected from the solenoid.

4. Depress the PT. RES. pushbutton.

5. The voltmeter pointer shouldreadwithin the 12V areaas shown

183

FIG. 16-Rotunda RE-235 Test Connections

B 1991-A

5. Clip the red pickup over thecoil-to-distributor high tension wire.


in black on the meter dial. If not,check for incorrect breaker pointspring tensionor for burnedor pittedpoints.

6. Connectthe high tensionwireto the distributor.

RE-881 Tester

1. Remove and ground the hightension wire from the centerof thedistributor.

2. "Bump" the starter with thestarter switch to close the breakerpoints. This will be indicatedby theloweht reading on the voltmeter. On

a car equipped with a transistorignition system, the starter isbumped by jumping between the"S" terminal of the solenoid andthe battery, with the ignitionswitch off and the coil lead brownwire disconnectedfrom the solenoid.

3. The voltmeter pointer shouldread in theblack OK PT. RES.area.If it doesn’t, check for improperbreakerpoint spring tension or forburnedor pitted points.

4. Connect the high tension wireto the distributor.

Disconnect the vacuum line. Ifnecessary,clean and mark the desired timing mark.

RE-235 Tester

1. Start the engine and allow itto warm up.

2. Operate the engine at the specified idle speedand point the timinglight toward the pointer. The desired timing mark should line upwith the pointer.If it doesn’t, loosenthe distributor hold down bolt androtate the distributor until the mark

184

IANY GOOD GROUND


81 992-A

IGNITION TIMING


cv.

KV

25

10A

20

‘15. PUG

* B 10

* C D ,0

DWELL-II I I

30 25 20 15 8CYL.

FIG. 19-NormalSuperimposed Primary Pattern


lines up with the pointer. Nowtightenthehold down bolt andcheckthe timing.

RE.651 Tester

1. Turn the rpm selector to the1000 position.

2. Depress the advance timingpushbutton.

3. Start the engineand allow it towarm up.

4 Operatethe engineat thespecified idle speed.

5. Turn the advance knob untilthe ignition advancemeter reads0°.

6. Point the timing light towardthe timing pointer. The desiredtiming mark should line up with thepointer. If it doesn’t, loosen the dis

tributor hold down bolt and rotatethe distributor until the desiredtiming markandpointerline up. Tightenthe distributor hold down bolt andcheckthe timing.

RE-881 Tester. The method oftesting is the same as the RE-65ltester with the exceptionof Step Iwhich should for theRE-881 read"turn the rpm selector to the 800position."

SUPERIMPOSED PRIMARYPATTERN

Procedure

RE-235 TESTER

1. With the engine running at

1000 rpm, turn the test selectorswitch to the primary PR!. position.

2. Adjust the parade control toposition the left end of the patternat the left verticalline on the screen.

3. Adjust the expand control sothat the right end of the patternisat the right vertical line on thescreen.

RE-651TESTER

1. Turn the rpm selector to the5000 position. Start the engineandadjustit to 1000 rpm.

2. Depressthe PRI pushbuttononthe console panel.

3. Adjust the paradeand expandcontrols to position the left end ofthe pattern at the left vertical lineon the screenand the right end ofthe pattern at the right vertical lineon the screen.

RE-881 TESTER. The test procedurefor the RE.-881 is the same

81993-A as the test procedurefor the RE-651except for the setting of the rpmselector. For the RE-881 tester, therpm selector is turned to the 1600position.

Results. A normal test pattern isshown in Fig. 19.

Point A indicates the spark plugline which is the time when thepoints open. At B, the coil energy isusedup sufficiently so that the plugno longer fires and only the energystoredin thebreakerpoint condenserremains.This coil/condenseroscillation which is indicatedin thepatternbetweenB and C is completelyusedup at C which is the points closemark. The portion of the patternbetweenC andD is the points closetime, which is cam angle or dwelltime. At D, the points again openand the firing cycle repeats.

If points A and C are below the

185

0

81994-A


horizontal 0 line, the batterypolarity is incorrect.This could be causedby a battery that is either installedincorrectly or improperly charged,causing a polarity reversal.

If the firing line is not below the0 line and there are no oscillationsat point C, there is an opencircuitat the coil high tension tower. Thiscould be causedby a broken wireinside the coil tower, or a brokencenter contact on the distributorrotor.

If the dwell time is too short, thebreaker points are incorrectly setthe larger the gap, the smaller thedwell.

If point A is at a reducedheight,andthe distanceto B is short or nonexistent,and theoscillationsat pointC are reducedin height, there is a

KV

lv - - - - - - - -

- - - - - - -

BD

50L. ..L

oLJ

20Li..

6CYL,

¶ 32’52O rr jiFIG. 20-Normal

LUG

*juKV

*

A

L

F;;5

0

Superimposed Secondary Pattern

high resistancein the coil primarycircuit. This could be causedby afouledplug, defectiveignition switch,or a bad wire or connection.If thescopepatternis still the sameafterthe above ignition parts havebeencheckedandprovensatisfactory,runthe 15 KV testto checkfor a gasketleak or a lean fuel mixture.

If point A is at a greatly reducedheight and there are no oscillationsat point B, the coil has a defectiveprimary winding or the condenserhasan excessiveseriesresistance.

If there is a variation at points Cand D, the cam lobes are uneven,the distributor shaft is bent, or thedistributor bushingsare worn.

SUPERIMPOSED SECONDARYPATTERN

Procedure

RE-235TESTER

1. With the engine running at1000 rpm, turn the test selectorswitch to thesecondarySEC. position.

2. Adjust the parade and expandcontrols so that the left end of thepatternis at the left vertical line onthe screenand the right end of thepattern is at the right vertical lineon the screen.

RE-651AND RE-881TESTERS.The procedureis the same as theprocedurefor the primary superimposed pattern except the SEC.pushbutton is depressedinstead ofthe PR! pushbutton.

Results.A normal test patternisshownin Fig. 20.

Point A is the points open time.The height of the patternat point Aindicates the high tension voltagerequiredto overcomethe sparkpluggapresistance.

Point B is the plug firing line.Notice that this portion of the pattern is quite thick. Rememberthatthis pattern is actually 8 firing patternssuperimposedoneon top of theother. This increasein thickness ofthepatternat B is causedby slightvariationsin theplug gap, distributorrotor gap and slight differences inthe resistanceof the individual sparkplug circuits.

The patternarea between pointsC and D shows the coil/condenseroscillations to be correct. No point

81996-A bounceat D indicatescorrectbreaker point spring tension.

The few so called dampedoscillations appearingat D arenormal andare causedby the surge of currentthrough the coil primary windingwhen the breakerpoints first close.

This current levels off and decreasesslightly toward the pointsopen position at E as indicatedbythe slight downward slope of thecurve at about the 15° mark on thecamangle scale.

To observe the coil/condenseroscillations and the dampedoscillations at D’ in greaterdetail, adjustthe expandcontrol so that the pattern area betweenpoint C and D’nearly fills the screen.

If there is erratic action at pointsC and D, and there is a blotchabovepoint E, thebreakerpoints areburnedor badly pitted.

If the length of B is reducedandthe patternbetweenC and D is notsuperimposed,there is a seriesgapin the coil high tension tower orwire.

If the line at B is sloping downward greatly resistor plugs willcausea slight slope, there is a highresistancein the spark plug wires,distributor cap or rotor.

.

10

20 6CYL.40 30I_J.I

*

0I I5 20 15 8 CYL

FIG. 21-is KY PatternIf point D1 is varying erratically,

the distributor is badly worn. If thisvariationis definite insteadof erratic,the advancemechanismin the distributor is defective.

If the dwell line betweenpointsD1 and E is not the smooth lineshown, there is a looseconnection inthe primary circuit. Check the primary circuit for loose connections,damagedwires or adefectivestarterswitch.

15 KV PATTERN

Procedure

RE-235TESTER. With the engineoperatingat 1000 rpm, turn the testselectorswitch to the 15 KV position. Adjust the expandandparadecontrols to produce the patternshown in Fig. 21.

RE-651 TESTER. With the rpmselectorat the 5000 position andtheengine operatingat 1000 rpm, depressthe 15 KY pushbutton.Adjustthe expandand paradecontrols toproducethepatternshownin Fig. 21.

RE-881 TESTER. With the rpmselectorat the 1600 position andtheengine operatingat 1000 rpm, depressthe 15 KY pushbutton.Adjustthe expand and paradecontrols toproducethepatternshownin Fig. 21.

Results. A normal 15 KV patternis shownin Fig. 21. The spark plugline A for the No. 1 spark plugis on the extremeright hand side ofthe screen.The remainderof the No.1 firing patternis on the left sideofthe screen. The remainder of thepatternsareshownfrom left to rightin their firing order.

With the exception of the No. 1spark plug line which should beshorter than the others, the patterns should be similar. If oneof thepatternsdiffers from the others, adjust the expandandparadecontrols

186

25

* -

B1995-A

187

‘30cv KV

* 25

10 ‘20

PLUGis

Be 1;

FIG. 22-30 KY Pattern81997-A

until that patternfills the screeninthe samemannerasin the secondarytest Fig. 20.

The following list of symptomswill refer to Fig. 20.

If the points open line A ishigher than the rest and the plugfiring line B is sloped downwardat an unusuallylarge slope, there isexcessiveresistancein the high tension wire to that cylinder or in thedistributor cap.

If the points openline A is lowand the firing line B is long andnearly straight, the spark plug isshortedout.

If the points open line A is lowand the firing line B is long andwide, the spark plug gap is out ofadjustment.

If there are no oscillations atpoints C or D, the coil primarywindings are partially shorted.

If the points open line A andthe oscillations at point D are bothdisplacedto the right on all cylinders, checkthe breaker points.

all of the points openlines Aareat varied heights, check the idleadjustmentof thecarburetoralwaysadjust the idle mixture on the richside.

30 KV PATTERN

Procedure

RE-235TESTER. With the enginerunning at 600 rpm, turn the testselectorswitch to the 30 KY position. Adjust the expand andparadecontrols to produce the patternshown in Fig. 22.

RE-651 TESTER. With the rpmselectorat the 5000 position andtheengineoperatingat 600 rpm, depressthe 30 KV pushbutton.Adjust theexpand and paradecontrols to produce the patternshown in Fig. 22.

RE-88l TESTER. With the rpmselectorat the 1600 position and theengineoperatingat 600rpm, depress

the 30 KY pushbutton. Adjust theexpandand paradecontrols to produce the pattern shown in Fig. 22.

Results. A normal 30 KV patternis shown in Fig. 22. The sparkplugline A for the No. I spark plugis on the extremeright hand side ofthe screen. The remainder of theNo. I firing pattern is on the leftsideof the screen.The remainderofthe patterns are shown from left toright in their firing order.

Notice the averageheight of thesolid part of the points open line.Increasethe speedof the engineandnotice the height of the dottedlines.The difference is the required ignition output under load. The maxirrium output should be between13.5and 15 KV.

If the maximum for one or moreof the plugs is above 15 Ky, checkthe complete circuits of theplugs for any trouble that wouldc:ause this resistance.If the maximum does not increase during theincrease in engine speed,check for

a fouled or improperlygappedsparkplug or for very low compression.

Remove the high tension wire atthe distributor cap for any plugexcept No. 1. Notice the changebetweenthe averagepoints openlineand the points open line of thecylinder with the high tension wireremoved. This height difference isthe coil reserve. The coil reserveshould be at least 30% of the maximum output. If it is less than 30%,replacethe coil.

Remove and do not ground onespark plug wire at the spark plug.If a plug firing line shows up on thescope for that cylinder, check theplug wire and distributor cap forbad insulation.

IGNITION SYSTEM TESTS-SUN 900 TESTER

TEST CONNECTIONS

Most of the ignition system canbetestedby using theSun 900 ScopeMotor Tester.Make the connectionsas follows Fig. 23.

PART 9-1 -GENERAL IGNITION SYSTEM SERVICE

TEST LEADS

9-11

FIG. 23-Sun 900 Tester Connections


1. Plug the power cord into aproper outlet.

2. Turn the AC masterswitch tothe ON position.

3. Turn the Tach-Dwell selectorswitchto the calibratorCAL. position and adjust the dwell calibratoruntil the meter pointer readson theSET LINE.

4. Turn the Tach - Dwell rpmswitch to the 5000 position.

5. Connect the Tach-Dwell leads;connect the RED insulator lead tothe primary distributor lead at thecoil. Connectthe BLACK insulatorlead to a good ground.

On a carequippedwith a transistor ignition system,connecttheRED insulator lead to the REDside of the tachometer block andthe BLACK insulator lead to theBLACK side of the tachometerblock.

6. Connectthe trigger pickup intothe circuit of the first spark plugin thefiring order.

7. Turn the Voltage Leakageunitcontrol counterclockwise to theTIMING position.

8. Connect a jumper lead fromthe distributor primary to a goodground.

9. Set the Voltage Leakageswitchto the 20 V position.

10. Connectthe Voltage Leakagetest leads;the RED leadis connectedto the battery side of the coil andthe BLACK lead is connectedto agood ground.

11. Removethe high tensionwirefrom the coil and leave the wiredisconnected.

12. Insert the scopepatternpickup into the coil tower and attachthe groundclip to a good ground.

13. Set the scopeground polarityswitch to the POSITIVE + position.

14. Turn the scopedisplay selectorto the SCOPE CHECK position andadjust the horizontal and verticalknobs until the traceappearson theZERO 0 line allow about 30secondsfor warm-up before adjustment.

CRANKING VOLTAGE

1. With the testerconnected,turnthe ignition switch ON. Make surethat the transmission is in neutraland that the parking brake is set.

2. Crank the engine, observethespeed and note the reading on thevoltmeter.

If the meter reads less than thespecified voltage, check for the following: weak battery, defectivecables, connections, switch, starter,by-passcircuit, or ignition circuit tocoil.

If the speed is uneven or slow,the engine or starting circuit isdefective.

BREAKER POINTS

1. With the motor tester connected,turn the scopedisplay selector to the INDIVIDUAL CYLINDER position.

2. Removethe jumper lead fromthe distributor to ground.

3. insertthecoil high tensionwireinto the scopepatternpickup.

4. Operate the engine at 1200rpm.

5. Observe the point open andpoint close signals Fig. 24. If anunusual point close signal is obtainedan unusualpoint closesignalis one that does not have a shortstraight downward line followed bya series of closely grouped rapidlydiminishing oscillations, check forpoor point contact, misalignedpoints, or weakpoint spring tension.

If an unusualpoint open signal is

188

obtained an unusual point opensignal is one that does not form afiring line that is straight up anddown, check for dirty or burnedpoints, or high series resistance.

COIL

Polarity

1. Removethe jumper lead fromthe distributor to ground, if it isstill connected.

2. Insertthe coil high tensionleadinto the scopepatternpickup.

3. Adjust the engine speedto 1200rpm.

4. Turn the scopedisplay selectorto the ALL CYLINDERS position,and adjust the patternlength controluntil all cylindersappearbetweenthevertical lines on both sides of thescreen.

5. Rotate the pattern shift control counterclockwiseuntil the lastpatternon the screenappearscomplete.

6. Observethe patterns,noting ifthey are upright or inverted Fig.24.

If they are inverted,checkfor thescopeground polarity switch in theMINUS - position, batterypolarity reversed, coil improperly connected,or incorrectcoil.

Primary and Secondary Tests.To check the coil for shorted oropen windings and for primary orsecondary resistance,calibrate theCondenser-CoilUnit asfollows:

1. Turn the AC switch to ON.2. Set the Condenser-Coil Unit

selectorswitch at the OHMS position.

3. Set the Condenser-Coilohmsswitch to the desired range.

4. Connectthe test leadstogether.5. Adjust the Condenser-Coilcali

brator until the meter pointer readsZERO on the ohms scale.

6. Disconnectthe test leads.7. Disconnect all leads from the

coil.INTS

POINTS OPEN

CLOSE

SECTIONINTERMEDIATE

SECTION DWELL SECTION

SHORTED OR OPEN WINDINGS.

1. Calibrate the Condenser-CoilUnit the ohm switch should be inthe OHMS position.

2. Connect the test lead, one toeach coil primary terminal. Observethe polarity.

3. Insert the coil pickup into thesecondarytower of thecoil andcon-

81 727-A fleet thegroundleadof the pickup toa good ground.

4. Turn the Condenser-CoilUnitFIG. 24-Typical Scope Pattern

PART 9-1-GENERAL IGNITION SYSTEM SERVICE 9-13

selectorswitch to the COiL TESTposition and observethe wave pattern visible on the coil test scope.

Referto Fig. 25 for checkingthedata obtained.

PRIMARY RESISTANCE

1. Calibrate the Condenser-CoilUnit set the ohm switch to theOHMS position.

2. Connect the test leads, one toeachprimary terminal of the coil.

3. Observethe meter reading andcompareit with specifications.

SECONDARY RESISTANCE

1. With the ohm switch set at theOHMS x 1000 position, calibratetheCondenser-CoilUnit.

2. Install the coil pickup test leadin the tower of the coil.

3. Connect the ohmmeter testleads,one to either primary terminaland the other to the open pigtailend of the coil pickup test lead.

4. Observethe meterreadingandcompareit with specifications.

If the meter reading exceeds20,000ohms, the secondarywindingis open.

CONDENSER

For the condensertests, calibratethe Condenser-CoilUnit as follows:

1. Set the selector switch to theCONDENSERposition.

2. Connectthe test leadstogether.3. After allowing approximately

one minute for the tester to warmup, adjust the calibrator until themeter pointer reads on the set lineat the right end of the meter scale.Do not change this setting duringthe tests.

Resistance

1. Connectthe test leads, one tothe primary terminal of the distributor andthe other to a groundon thedistributor body.

2. With the condensertest switchin the SERIES RESISTANCE posi

tion, the meter should read in theblack bar at the right end of thescale.

3. Move the condenserpigtail. Ifa deflection of the meter is noted,the pigtail is making poor contactandthecondensershouldbe replaced.

If the readingis outside the blackbar, move the groundedleadto thebody of the condenser.If the reading improves, the condenseris notproperly groundedto the distributorhousing.

Capacity

1. Turn the condensertest switchto the CAPACITY position.

2. Read thered scaleof the meter0.5 for the microfaradcapacityofthe condenserbeingtested.

3. Refer to the specifications forthe recommendedcondenser capacity.

if the readings are not withinspecificationsreplace the condenser.

Leakage

1. Turn the condensertest switchto the LEAKAGE position.

2. The meter should now read inthe black bar at the left end of thescale if the condenserleakageis satisfactory.

If the meter pointer readsoutsidethe black bar, the condenserinsulation is leaking and the condensershould be replaced.

NOTE: If the condenserdoes notmeet specificationswhile mountedinthe distributor,removethe condenserandretestit. The sameprocedureisfollowed as above. If the condensertests badin the distributor, but testsgood when removed,thereis a shortor ground in the distributor primarycircuit. Inspectthe insulation of thedistributor primary terminal and theinternal circuit of the distributor.

FIRING VOLTAGE

I. Remove the jumper from thedistributor to ground.

2. Insert the coil high tensionleadinto the scopepickup.

3. Adjust the engine speed to1200 rpm.

4. Turn the scopedisplay selectorto the ALL CYLINDERS position,and adjust the patternlength controluntil all of the cylinders appearbetweenthe vertical lines on the screen.

5. Rotate the patternshift controlcounterclockwiseuntil the last pattern on the screenappearscomplete.

6. Observethe height of each firing line, on the scope, andcomparefor uniformity and height Fig. 24.

If the firing voltagesare uniform,but high, checkfor worn sparkplugs,late ignition timing, lean fuel mixture, too large a rotor gap, or abreakin the coil wire.

If the firing voltages are uneven,check for worn spark plugs, unevencompression, breaks in spark plugwires, or a cocked or worn distributor cap.

AVAILABLE VOLTAGE

1. Makethe sameconnectionsandadjustmentsas for the firing voltagetest above.

2. Disconnecta spark plug wirewith a pair of insulatedpliers.

3. Hold the wire away from agroundandnoticetheupwardextentof the pattern on the scope.

If the availablevoltage is less than20 KV, checkfor excessiveresistancein the primary circuit, low primaryinput voltage, defective coil, dwellless than specified, or defectivesecondaryinsulation.

SECONDARY INSULATION

1. Continue with the same connections and adjustmentsas in thelast two tests.

2. Observethe downward extentof the patternof the sparkplug withthe wire removed.

3. Connectthe sparkplug wire.4. Perform this test on all of the

cylinders trigger cylinder may betestedin the SCOPE CHECK position.

if the lower extent is not at leasthalf the size of the upper extent,check for insulation leakage in thecoil, coil tower, rotor, coil wire, distributor cap, or spark plug wire.

SECONDARY RESISTANCE

1. The connections and adjustments for this test are the same asfor the last three tests, except forthe scope display selector switchwhich is now placed in the ALLCYLINDERS position.

189

FIG. 25-Coil Test Patterns


2. Observeandcomparethe sparkline Fig. 24 of the patterns forlength,height,angleandoscillations.

If all cylinders areaffected, checkfor high resistancein the coil tower,coil wire, rotor, or distributor captower; also check for an accumulation of depositson the spark plugs,or poor contact between the rotoranddistributor cap.

If one or more cylinders areaffected,checkfor high resistanceinthe distributor cap tower, sparkplugwires, or sparkplugs.

SPARK PLUGS

To test the sparkplugs on the car,connectthe motor testerin the samemanneras for the firing voltagetest.

1. Turn the displayselectorswitchto the ALL CYLINDERS position;rotatethe patternshift control in theFULL CLOCKWISE position.

2. Momentarilyacceleratethe engine to about 2000 rpm and returnto 1200 rpm.

3. Observethe rise of the firinglines during the momentaryengineacceleration.

If one or more of the firing linesis higher than the others, check forwide plug gap, open spark plug resistor wire, or badly deterioratedelectrodes.

If one or more of the firing linesis lower than the others, check forspark plug fouling, fiashover, orcrackedinsulators.

DISTRIBUTOR DIAPHRAGMLEAKAGE AND FREENESSOF OPERATION

These tests can be made with thedistributor installed on the engine.The testsaresufficient for an enginetune-up.However, if there are indicationsthat the sparkadvanceis notfunctioning properly, remove thedistributor from the engine andcheck it on a distributor test setfollowing the instructions under"Distributor SparkAdvance."

Checkthe vacuum advancemechanism for freenessof operation bymanually rotating the breakerplatein the directionof rotation. Do notrotate the plate by pushing on thecondenser or the breaker points.Use a hook or other suitable instrument to rotate the plate. Thebreaker plate should turn withoutbinding and return to ¶ts originalposition when released.If thebreaker plate binds, remove the plate.Clean, inspect andlubricate it as describedfor the particular distributor.

To checkthe diaphragmfor leak-age:

1. Remove the vacuum line fromthe distributor. Adjust the vacuumpressureof a distributor testerto itsmaximum position. Hold your handover the endof the tester’svacuumhoseandnote the maximumreadingobtained.Do not exceed25 inchesHg.

2. If the maximum reading is 25inchesHg or less,connectthetester’svacuumline to the vacuumfitting onthe diaphragm without changingany of the adjustments.The maximum gauge readingshould not beless than it was in step 1. If it isless, the diaphragm is leaking andshould be replaced.

DISTRIBUTOR BREAKER PLATEWEAR

A worn breaker plate will causethe breaker point gap and contactdwell to changeas enginespeedandload conditions are varied. Mountthe distributor in a distributor testerfollowing the instructions in this section of the manual.

Adjust the test to 0 advance,0 inchesvacuum,and1000 rpm.Adjust the dwell angle to 26°. Applyvacuum to the distributor diaphragmandincreaseit very slowly while observing the indicated dwell angle.The maximumdwell angle variationshould not exceed 6° when goingfrom zero to maximum vacuum atconstant rpm. If the dwell anglevariation exceedsthis limit, there isexcessivewear at the stationarysub-plate pin or the diaphragm rod isbent or distorted.

DISTRIBUTOR SHAFT END PLAY1. Removethedistributor from the

190

engine.2. Place the distributor in the

holding tool and clamp it in a vise.3. Push the distributor shaft up

ward as far as it will go, then checkthe end play with a feeler gaugeplaced between the collar and thedistributor base.The endplay shouldbe within the specified limits.

If the shaft end play is not tospecifications,check the location ofthe distributor shaft collar.

DISTRIBUTOR TESTS-ROTUNDA RE-1416 TESTER

MOUNTING DISTRIBUTOR

1. Clamp the distributor securelyin the distributor supportarm clampso that it will not turn in its mounting.

2. Loosenthe hand-operatedlocking screwonthesideof thedistributorsupport arm and adjust the supportarm column up or down by turningthecrankon theknob at thetop of thecolumn until the distributor shaft oradapter shaft can be securelyfastenedin the driving chuck. Useadaptershafts provided when driving distributors having short shafts.

3. Securelytightenthe drive chuckto the distributor drive shaft bymeansof the chuck key, attachedbya chain to the Syncrograph

4. Rotate the drive chuckby handto make sure the distributor shaftturns freely and then tighten thelocking screwon the distributor support arm.

FIG. 26-TestingTransistor Ignition Distributor

5. Connect the Syncrographtestlead to the primary or distributor-transistorleadwire of the distributor.Since the transistor ignition distrib

81990-A utor does not have a condenser,itwill be necessaryto install one inthe circuit of the testerFig 26.

BREAKER POINT RESISTANCE

1. Turn thetest selectorto POINTRES. position.

2. Revolvethechuck by handuntilthe distributor breaker points areclosed.

3. The meter pointer on the camangle meter should read in the OKzone at the left side of the meterscale If the meter pointer does notfall in the OK zone, thereis excessiveresistancecausedby a faulty contactacrossthe distributor points, a faultyprimary lead or a poorly groundedbaseplate.A faulty contactacrossthedistributor points indicatesimproperspring tension or burned or pittedpoints


INSULATION AND LEAKAGE

1. Turn the test selector to thecam angle position and revolve thechuck by hand until the distributorbreakercontactsare open

2. The cam angle meter shouldshow a zero reading. If a zero reading is not obtained,a short circuit toground exists

A short could be causedby poorprimary or distributor-transistorleadwire insulation, a shortedcondenseror a short betweenthe breakerarmandbreakerplate

MECHANICAL OPERATION

1. Turn the test selector to theSYNCHRO. position and check tomakesure the drive chuck is securelytightenedon the distributor shaft.

2. Turn the motor control switchto the left to correspondwith thedirection of rotation, as listed in therotation column of the distributorspecifications.

If it is necessaryto reverse therotation of the drive motor, turnthe motor control switch to theOFF position and allow the chuckto cometo a complete stop beforereversing the switch.

3. Adjust the rpm control to varythe distributor speed between 400and 4000 enginerpm or at the maximum speedof the engineon whichthe distributor is used. Erratic orthin faint flashesof light precedingthe regular flashes as the speed ofrotation is increasedcan be due toweak breaker arm spring tension orbinding of the breaker arm on thepivot pin

. Operate the distributor at approximately 2500 enginerpm.

5. Move the protractor scalewith

the adjustmentcontrol so that thezero degree mark on the scale isoppositeoneof the neonflashes.Thebalanceof all the flashesshould comewithin 1°, plus or minus, evenlyaroundthe protractorscale.A largervariation than 1° or erratic or wandering flashes may be causedby aworn cam or distributor shaft or abent distributor shaft.

DWELL ANGLE

1. Turn the cylinder selector tothe figure correspondingto thenumber of lobes on the cam of the distributor being tested.

2. Turn the test selectorswitch tothe cam angle position and operatethe distributorat approximately1000enginerpm.

3. Adjust the distributor breakerpoint gap to the dwell angle shownin the specifications.

DISTRIBUTOR SPARKADVANCE

The spark advanceis checkedtodetermineif the ignition timing advances in proper relation to enginespeedand load.

1. Check the contact dwell. If thecontact dwell or the breaker pointgap is not within specifications,adjust the breakerpoints.

2. Check the breaker arm springtension andadjust it if necessary.

FIG. 28-VacuumAdvance Adjustment

The dual advancedistributor hastwo independently operated sparkadvancesystems.Eachsystem is adjusted separately. Adjust the centrifugal advance before adjustingthe vacuum advance.

Centrifugal Advance

1. Do not connectthe test setvacuum line to the diaphragm.Set thetest set to 0° advanceand the initialrpm settinglisted in thespecifications.

2. Operate the distributor in thedirection of rotation counterciock

191

wise andslowly increasethe rpm tothe setting specifiedfor the first advancereadinglisted in the specifications.

If the correctadvanceis not indicatedat this rpm, stopthe distributorand bend one spring adjustmentbracket to change its tension Fig.27. Bend the adjustment bracketaway from thedistributor shaft todecreaseadvance increase springtension and toward the shaft toincrease advancedecreasespringtension. After the adjustment ismade,identify the bracket.

3. After an adjustmenthas beenmadeto onespring, checkthe minimum advancepoint again.

4. Operate the distributor at thespecifiedrpm to give an advancejustbelowthe maximum. If this advanceis not to specifications,stop thedistributor and bend the other springbracketto give the correctadvance.

5. Check the advanceat all rpmsettings listed in the specifications.Operatethe distributor both up anddown the rpm range.

Vacuum Advance

1. Connect the test set vacuumline to the fitting on the diaphragmand turn the vacuumsupply switchon.

2. Set the test set to 0° advance,0 vacuum,and at 1000 rpm.

3. Check the advanceat the firstvacuum setting given in the specifications. -

SPACING WASHERS

4. If the advance is incorrect,change the calibration washers between the vacuum chamber springand nut Fig. 28. After installingor removing the washers, positionthe gasket in place and tighten thenut. The addition of a washerwilldecreaseadvanceand the removal

B20 11-A of a washer will increase advance.5. After one vacuum setting has

beenadjusted, the othersshould bechecked.Do not changethe originalrpm setting when going to a different vacuum setting. If the othersettings are not within limits, it indicatesincorrectspring tension, leakage in the vacuum chamberand/orline, or the wrongfiber stop hasbeeninstalled in the vacuum chamberofthe diaphragmhousing.

DISTRIBUTOR TESTS-ROTUNDA RE-236 TESTER

MOUNTING DISTRIBUTOR

1. Adjust the distributor supportarm in relation to the distributorshaft length.

FIG. 2l-CentrifugalAdvance Adjustment


2. Set the distributor in the support arm and enter the lower endof the distributor shaft in the Syncrographchuck.

3. Tighten the chuck on the distributor shaft, using the wrench locatednearthe supportarm column.

4. Align the distributor shaft byshifting the supportarm anddistributor, then tighten the clamp screw.

5. Clamp the distributor securelyin thedistributor supportarm clampso that it will not turn in its mounting.

MECHANICAL OPERATION

1. Turn the OFF, SET, CAM,SYNC. switch to SET.

2. Adjust the SET TACH controlso the tachometerpointer is on theSET line.

3. Turn the OFF, SET, CAM,SYNC. switch to SYNC. position.

4. Turn the MOTOR switch to theLEFT position.

5. Adjust the speedcontrol to varythe distributor speed between400and4000 enginerpm, or at themaximum speedof the engineon whichthe distributor is used. Erratic orthin faint flashesof light precedingthe regular flashes as the speed ofrotation is increasedcan be due toweakbreakerarm spring tensionorbinding of the breaker arm on thepivot pin.

6. Operate the distributor at approximately 2500 engine rpm andmovethe protractorscaleso that thezero degreemark on the scaleis opposite one of the neon flashes. Thebalance of all the flashes shouldcomewithin 1°, pius or minus, evenly around the protractor scale. Avariationlargerthan 1° or erraticorwanderingflashesmay be causedbya worn cam or distributor shaft ora bent distributor shaft.

DWELL ANGLE

1. Turn the OFF, SET, CAM,SYNC. switch to the CAM position.Operatethe distributorat about1000rpth.

2. Adjust the breaker point gapuntil the cam angle is to specifications.



1. Check the contactdwell. If thecontact dwell or the breaker point

gap is not within specifications,adjust the breakerpoints.

2. Check the breaker arm springtension andadjust it, if necessary.

The dual advancedistributor hastwo independently operated sparkadvancesystems.Eachsystemis adjusted separately.Adjust the centrifugal advance before adjustingthe vacuum advance.

Centrifugal Advance

1. Do not connect the test setvacuum line to the diaphragm.Setthe test set to 00 advanceand theinitial rpm setting listed in thespecifications.

2. Operate the distributor in thedirection of rotation counterclockwise and slowly increasethe rpmto the setting specified for the firstadvancereading listed in the specifications.

If the correctadvanceis not indicated at this rpm, stop the distributor and bend one spring adjustment bracket to change its tensionFig. 27. Bend the adjustmentbracket away from the distributorshaft to decreaseadvanceincreasespring tension and towardthe shaftto increaseadvancedecreasespringtension. After the adjustment ismade, identify the bracket.

3. After an adjustmenthas beenmadeto onespring, check theminimum advancepoint again.

4. Operate the distributor at thespecifiedrpm to give an advancejustbelow the maximum. If this advanceis not to specifications,stop the distributor and bend the other springbracket to give the correctadvance.

5. Check the advanceat all rpmsettings listed in the specifications.Operatethe distributor both up anddown the rpm range.

Vacuum Advance

1. Connect the test set vacuumline to the fitting on the diaphragm.

2. Set the test set to 0° advance,0 vacuum,andat 1000 rpm.

3. Check the advanceat the firstvacuum setting given in the specifications.

4. If the advance is incorrect,change the calibration washersbetween the vacuum chamber springand nut Fig. 28. After installingor removingthewashers,positionthegasket and tighten the nut. Theaddition of a washer will decreaseadvance and the removal of awasher will increase advance.

5. After one vacuum setting has

beenadjusted, the othersshould bechecked.Do not change the original rpm setting when going to adifferent vacuum setting. If theother settings are not within limits,there is .incorrect spring tension,leakagein the vacuumchamberand/or line, or the wrong fiber stop hasbeeninstalled in the vacuum chamber of the diaphragmhousing.

DISTRIBUTOR TESTS-SUN DT-600 TESTER

MOUNTING

1. Using the elevationcrank, raisethe clamp arms high enoughto permit the shaft of the distributor toclear the drive chuck.

2. Position the distributor in theclamp with the vacuum diaphragmpointing toward the right. Tightenthe clamp armssecurelyaroundthedistributor body. Install the properadapterto thevacuum diaphragm.

3. Lower the distributor with theelevation crank until the gear or¾ inch of the tip of the distributorshaft entersthe drive chuck, or untilthe shaft engagesthe adapter if anadapteris being used. Do not bottom the distributor shaft in thechuck.

4. Tighten the chuck. Do not tryto raise or lower the distributorafter thechuckhasbeentightened.

CONDENSER TESTING

Condensersshould be testedforseriesresistance,capacity and leakage. The preparationprocedure isas follows:

1. Trip the motor switch to theproper position for the rotation ofthe distributor being tested.

2. Turn the condensertest selector switch to the SERIES RESISTANCE position andconnectthe con-densertest leads together.

3. Turn the condenser calibratecontrol clockwise from the OFF position.

4. Allow thetesterto warm up forapproximately30 secondsand thenadjust the calibratecontrol until thecondensermeter readson the SETLINE.

5. Rotate the distributor sha’t untilthe cam holds the breaker pointsopen.

6. Separatethe test leads andconnect one to the distributor primaryleadand the other to the distributorbody.

SeriesResistance.Turn the condenser test selector switch to the

9-16 192


SERIES RESISTANCE position.The condenser meter should read inthe black bar on the right endof thescale.

Capacity. Turn the condensertestselectorswitch to the CAPACITYposition. The condensermeter willnow readthecapacityin microfarads.Comparethis reading with specifications.

Leakage.Turn the condensertestselector switch to the LEAKAGEposition. The condensermetershouldread in the black bar at the left ofthe scale.

Turn the test selectorswitch tothe SERIES RESISTANCE positionand turn OFF the condensercalibrator before disconnectingthe testleads.

DISTRIBUTOR RESISTANCE

1. With the motor switch in theproper position for the rotation ofthe distributor being testedand thespeed set at ZERO rpm, clip thetester’s distributor and ground leadtogether.

2. Set the tachometerdwell selector switch to the CALIBRATE position andadjustthe dwell regulatoruntil the dwell meter reads on theSET LINE.

3. Separate the leads and connectthe tester’s distributor lead to thedistributor primary or distributor-transistor lead. Since the transistorignition distributor does not havea condenser, it will be necessaryto incorporate one in the test circuit Fig. 26. The tester groundleadshould now be connectedto thedistributor body.

4. Rotate the chuck by handuntilthe points are closed. The dwellmeter should read in the black barat the right end of the scale.

If it does not read in the blackbar,movethe tester’sdistributorwirestep by step through the circuit toward the ground. When there is ameasurabledifference between twopoints, checkthat areafor the causeof the resistance.

CAM LOBE ACCURACY

1. Connectthe test leadsfollowingthe directions in the distributor resistancetest.

2. Turn theswitch to the 8

3. Adjust the1000 rpm.

4. Rotate the degreering of thetester until the ZERO on the ringlines up with one of the flashes.

5. Observethe positions of the remaining flashes.If theflashesarenotevenly spacedwithin ±10, checkfor a worn cam, worn distributorshaft or a bent distributorshaft.

DWELL ANGLE

This test hasthe sameconnectionsas the precedingtest, thereforetheycan be doneat the sametime.

Adjust the speedto 200 rpm andnotice the dwell reading. If it is notwithin specifications, adjust thepoints until the properdwell is obtained. Now increasethe speedandcheckthe dwell reading. If the reading changesmore than two degrees,check for a worn distributor shaftor worn bushings.



1. Check the contactdwell. If thecontact dwell or the breaker pointgap is not within specifications,adjust the breaker points.

2. Check the breaker arm springtension and adjust it if necessary.

The dual advancedistributor hastwo independently operated sparkadvancesystems.Eachsystemis adjusted separately.Adjust the centrifugal advancebefore adjustingthevacuum advance.

Centrifugal Advance

1. Do not connectthe test set vacuum line to the diaphragm.Set thetest set to 0° advanceandthe initialrpm settinglisted in thespecifications.

2. Operate the distributor in thedirection of rotation counterciock

wise andslowly increasethe rpm tothe setting specifiedfor the first advance reading listed in the specifications.

If the correctadvanceis not indicatedat this rpm, stopthedistributorand bend one spring adjustmentbracket to change its tension Fig.27. Bend the adjustment bracketaway from the distributor shaft todecreaseadvance increase springtension and toward the shaft toincrease advance decreasespringtension. After the adjustment ismade,identify the bracket.

3. After an adjustmenthas beenmadeto onespring, checkthe minimum advancepoint again.

4. Operate the distributor at thespecifiedrpm to give an advancejustbelow the maximum. If this advanceis not to specifications,stop thedistributor and bend the other springbracket to give the correctadvance.

5. Check the advanceat all rpmsettings listed in the specifications.Operatethe distributor both up anddown therpm range.

Vacuum Advance

1. Connect the test set vacuumline to the fitting on the diaphragm.

2. Set the test set to 00 advance,0 vacuum,andat 1000 rpm.

3. Check the advanceat the firstvacuum setting given in the specifications.

4. If the advance is incorrect,change the calibration washersbetween the vacuum chamberspringandnut Fig. 28. After installing orremoving the washers,position thegasket and tighten the nut. The addition of a washer will decreasethe advance and the removal of awasher will increasethe advance.

5. After one vacuum setting hasbeenadjusted, the othersshould bechecked. Do not change the original rpm setting when going to adifferent vacuum setting. If theother settings are not within limits,it indicates incorrect spring tension,leakagein thevacuumchamberand/or line, or the wrong fiber stop hasbeeninstalled in the vacuum chamber of the diaphragmhousing.

B COMMON ADJUSTMENTS AND REPAIRSBREAKER POINTS

ADJUSTMENT

NewBreaker Points. Newbreaker points can be adjusted with a

feeler gauge,scopeor a dwell meter.To adjustthe breakerpoints with

a feeler gauge:1. Check and adjustbreakerpoint

alignment. Rotate the distributor

camuntil the rubbingblock rests onthe peak of a camlobe.

If the car is equipped with atransistor ignition and the starter is going to be tapped to place

193

tachometer dwellposition.distributor speedto


the breaker point assembly on thepeak of the cam, proceed as follows: connect a juniper betweenthe "S" terminal of the solenoidand the battery with the ignitionswitch off and the coil lead brownwire disconnectedfrom the solenoid.

2. Insert the correct blade of acleanfeelergaugebetweenthebreaker points Fig. 29. The gap shouldbe set to the largeropeningbecausethe rubbing block will wear downslightly while seatingto the cam.

3. Apply a light film of distributorcam lubricantto the camwhen newpoints are installed. Do not use engine oil to lubricate the distributorcam.

4. Set the ignition timing.If a scopeor a dwell meter is used

to adjust new points, be sure thepoints arein properalignment. Also,

CONTACTAREA

- CENTERED

CORRECTALIGNMENT

CONTACT- AREA NOTIiCENTERED

MISALIGNMENTOF CENTERS

CONTACT-

- :- AREA NOTCENTERED

MISALIGNMENTOF POINT FACES B1019-A

FIG. 30-Breaker Point

FIG. 3l-AligningBreaker Points

set the contactdwell to the low setting. New points must be set to thelow dwell as the rubbing block willwear down slightly while seating tothe cam.

Used Breaker Points. If the gapof used breaker points is beingchecked,use a scopeor dwell meterto test the contact dwell. It is notadvisableto use a feeler gauge toadjust or to check the gap of usedbreakerpoints becausetheroughnessof the points makesan accurategapreading or setting impossible.Cleanthe breakerpoints. Check the contact dwell following the instructionsunder "Ignition SystemTests". Thecontactdwell should be to specifications. Check and adjust the ignitiontiming.

FIG. 33-AdjustingSpring Tension

ALIGNMENT

The vented-type breaker pointsmustbe accuratelyalignedandstrikesquarely in order to realizethe fulladvantagesprovided by this design,andassurenormalbreakerpoint life.Any misalignment of the breakerpoint surfaceswill causeprematurewear, overheatingandpitting.

1. Turn the camso that thebreaker points are closed and check thealignmentof the points Fig. 30.

If the carhasa transistor ignition system, refer to the adjustment of new breaker points forthe proper starter tapping procedure.

2. Align the breaker points tomake full face contact by bendingthe stationarybreakerpoint bracketFig. 31. Do not bendthebreakerarm.

3. After the breaker points havebeen properly aligned, adjust thebreakerpoint gap or dwell.

FIG. 29-Adjusting NewBreaker Point Gap

STATIONARY BRACKET B2012-A

LESS TENSION 82013-A

FIG. 32-CheckingBreaker Point Spring TensionAlignment FIG. 34-Timing Marks


ADJUSTING SPRING TENSION

Correct breakerpoint spring tension is essential to proper engineoperationand normal breakerpointlife. If the spring tension is toogreat, rapid wear of the breakerarmrubbingblockwill result, causingthebreakerpoint gap to close up andretardthe sparktiming. If thespringtension is too weak, the breakerarmwill flutter at high engine rpm resulting in an enginemiss.

To checkthe spring tension, placethe hookedendof the spring tensiongauge over the movable breakerpoint. Pull the gauge at a rightangle 90° to the movable armuntil the breakerpoints just start toopen Fig. 32. If the tension is notwithin specifications,adjustthe springtension.

To adjust the spring tension Fig.33:

1. Disconnectthe primary or distributor-transistorleadwire, andthecondenserleadif so equipped,at thebreakerpoint assemblyprimary terminal.

2. Loosen the nut holding thespring in position. Move thespringtoward the breaker arm pivot todecreasetension and in the opposite direction to increasetension.

3. Tightenthelock nut, thencheckspring tension.Repeatthe adjustmentuntil the specified spring tension isobtained.

4. Install the primary or distributor-transistorleadwire, andthecondenser lead if so equipped, withthe lock washer andtighten the nutsecurely.

IGNITION TIMING

TIMING MARK LOCATIONS

The crankshaftdamperFig. 34has 15 timing marks ranging fromtop deadcenter TDC to 30° before top deadcenterBTDC. Referto specificationsfor the correctignition timing.

ADJUSTMENT

The procedurefor adjusting theignition timing is covered under"Ignition SystemTests".

SPARK PLUG WIREREPLACEMENT

When removingthewiresfrom thespark plugs, grasp the moulded caponly. Do not pull on thewire becausethe wire connectioninside the cap

maybecomeseparatedor the weathersealmaybe damaged.

A typical ignition wiring installation is shown in Fig. 35.

REMOVAL

1. Disconnect the wires from thesparkplugs anddistributor cap.

2. Pull thewires from thebracketson the valve rocker arm covers andremovethe wires.

3. Remove the coil high tensionlead.

INSTALLATION

1. Insert eachwire in the propersocketof the distributor cap. Be surethe wiresareforcedall the way downinto their sockets.The No. 1 socketis identified on the cap. Install thewires in a counterclockwisedirection

FIG. 36-GappingSpark Plugs

in the firing order 1-5-4-2-6-3-7-8starting at the No. 1 socket. Cylindersarenumberedfrom front to rear;right bank 1-2-3-4, left bank 5-6-7-8.

2. Removethe bracketsfrom theold spark plug wire set and installthem on the new set in the samerelative position. Install the wires inthe bracketson the valve rockerarmcovers Fig. 35. Connectthe wiresto the propersparkplugs. Install thecoil high tension lead. Be sure theNo. 7 spark plug wire is positionedin thebracket as shown in Fig. 35.

SPARK PLUGS

REMOVAL

1. Remove the wire from eachsparkplug by graspingthe mouldedcap of thewire only. Do not pull onthe wire becausethe wire connection inside the cap may becomeseparatedor the weather sealmaybe damaged.

2. Clean the area around eachsparkplug port with compressedair,then removethe sparkplugs.

ADJUSTMENT

Setthe sparkplug gapby bendingthe groundelectrodeFig. 36.

INSTALLATION

1. Install the spark plugs andtorqueeach plug to 15-20ft-lbs.

When a new sparkplug is installedin a new replacementcylinder head,torquethe plug to 20-30ft-lbs.

2. Connect the spark plug wires.Pushall weathersealsinto position.

RESISTANCE WIREREPLACEMENT

The primary resistance wire ischecked for excessiveresistanceasoutlined under "Resistance WireTest".

195

FIG. 35-Ignition Wiring


FIG. 3l-Cleaning PlugElectrode

To replacethe resistancewire:1. Remove the instrument panel

lower covers.2. Disconnect the resistancewire

pink or black from the multiplemolded connectorat the PowerBox.This connectoris the secondfromthe top of the Power Box, and thepink or black resistancewire plugsinto the upper right corner of theconnector.

3. Cut off the old resistancewireat the point whereit entersthemain14401 wiring loom.

4. Connectthe replacementpinkor black wire to the multiple connector at thePowerBox.

5. Route the replacementwire asstraight as possibleunderthe instrument panel,to theconnectorneartheignition switch.

6. Disconnect the old wire at thequickdisconnectredwire with greenconnector near the ignition switchandconnectthereplacementwire.

7. Cut off the old resistancewirewhereit entersthemain wiring loom.

8. Tape the replacementwire tothemain wiring loom.

IDENTIFICATION I CAUSED BYWet, sludgy deposits. Excessive oil entering combustion

chamber through worn rings andpistons, excessiveclearancebetweenvalve guides and stems,or worn orloosebearings.

Dry, black,posits.

fluffy de- Incompletecombustioncausedby toorich a fuel-air mixture or by a defective coil, breakerpoints or ignitioncable.

White, burned, or Inefficient engine cooling, or engineblistered insulator overheatingcausedby improperigninoseanderodedelec- tion timing, wrong typeof fuel, loosetrodes. spark plugs, or too hot a plug, low

fuel pumppressure.

Rusty brown to gray-ish-tanpowderdeposit

Regular or unleadedgasoline.

andminor electrodeerosion.

White, powdery de- Highly leadedgasolines.posits.

Hard, bakedon black Too cold a plug. Weak ignition, decarbon. fective fuel pump, dirty air cleaner,

too rich a fuel mixture.

Hardandscratchy Formedwhenfinesandparticlescombine with anti-knock compoundsinthe fuel. Most common industryareas.The plugs cannot be cleaned.

Deposits, accumulatedafter a longperiodof misfiring, suddenlyloosenedwhen normal combustion chamberdepositsarerestoredafter new plugsare installed. During a high speedrun these deposits are thrown intothe plug. 81005-E

9-20 196

I- 781390-B

FIG. 38-Spark Plug Inspection


0 CLEANING AND INSPECTIONSPARK PLUGS

Clean the plugs on a sand blastcleaner,following themanufacturer’sinstructions. Do not prolong the useof the abrasiveblast as it will erodethe insulator. Remove carbon andother depositsfrom the threadswitha stiff wire brush. Any deposits willretardtheheatflow from the plug tothe cylinder headcausingsparkplugoverheatingand pre-ignition.

Clean the electrodesurfaceswitha small file Fig. 37. Dresstheelectrodesto secureflat parallel surfacesonboth thecenterandsideelectrode.

After cleaning,examinethe plugcarefully for crackedor broken insulators,badly pitted electrodes,andother signs of failure. Replaceas required.

Examine the firing ends of thespark plugs, noting the type of deposits and the degree of electrodeerosion.Referto Fig. 38 for thevarious typesof spark plug fouling andtheir causes.

DISTRIBUTORS

Soak all parts of the distributorassembly except the condenser,breaker point assembly, lubricatingwick, vacuumdiaphragm,distributorbase oil seal, and electrical wiringin a mild cleaningsolvent or mineralspirits. Do not use a harsh cleaningsolution. Wipe all parts that can notbe immersedin a solventwith a cleandry cloth.

After foreign deposits have beenloosenedby soaking, scrub the partswith a soft bristle brush.Do not usea wire brush,file, or other abrasiveobject. Dry the parts with compressedair.

Examine the bushing surface ofthe distributor shaft andthe bushingfor wear. The dual advancedistributor hasonebushing.The minimumallowableshaft diameterat thebushing is 0.4675inch andthe maximumallowableinsidediameterof thebushing is 0.4690 inch. Replace wornparts.

Inspectthe distributor cam lobesfor scoringandsignsof wear. If anylobe is scoredor worn, replacethecamassembly.

Inspectthebreakerplate assemblyfor signs of distortion. In addition,inspect the stationary sub-plateforworn nylon contactbuttons.Replacethe breakerplate assemblyif it is defective.

The breaker point assembly andcondenserif so equipped shouldbe replacedwheneverthe distributoris overhauled.

Inspect all electrical wiring forfraying, breaks,etc.,andreplaceanythat arenot in goodcondition.

Check the distributor base forcracksor other damage.

Check the diaphragm housing,bracketand rod for damage.Checkthe vacuum line fitting for strippedthreadsor other damage. Test thevacuumfittings, caseanddiaphragmfor leakageasexplainedunder "Distributor Tests".Replaceall defectiveparts.

197

9-22 198

PART, DUAL

LADVANCE DISTRIBUTORS

Section Page Section Page1 Description and Operation 9-22 3 Removal and Installation 9-23

2 In-Car Adjustments and Repairs 9-22 4 Major RepairOperations 9-24

fl DESCRIPTION AND OPERATIONThe dual advancedistributor Fig.

1 has two independentlyoperatedsparkadvancesystems.A centrifugaladvancemechanismis locatedbelowthe stationarysub-plateassemblyanda vacuum operated spark controldiaphragmis locatedon the side ofthe distributor base. As speed increases,the centrifugalweightscausethe cam to advanceor moveaheadwith respectto the distributor driveshaft. The weights turn the cam bymeansof a stop plate that has twoslots, which fit over pins in the

weights. The slots determine themaximum amount of advance,andthe rate of advanceis controlled bycalibratedsprings.

The vacuum advancemechanismhasaspring-loadeddiaphragmwhichis connected to the breaker plate.The spring-loaded side of the diaphragm is airtight and is connectedthrougha vacuumline to thecarburetor throttle bore. Whenthe throttleplatesopen, the distributor vacuumpassageis exposedto manifold vacuum, which causesthe diaphragmto

move against the tension of thespring. This action causesthe movable breaker plate to pivot on thestationary sub-plate. The breakerpoint rubbing block, which is positioned on the opposite side of thecamfrom the pivot pin, then movesagainstdistributor rotation and advancesthesparktiming. As themovable breaker plate is rotated fromretardposition to full advanceposition, the dwell decreasesslightly.This is becausethe breaker pointrubbingblock andthe camrotateondifferent axes.

U IN-CAR ADJUSTMENTS AND REPAIRSDISASSEMBLY

REMOVAL OF COMPONENTS

1. Removethe primary wire fromthe coil or the distributor-transistor

lead from the quick disconnect.Unsnap the distributor cap retainingclips, lift the distributor cap off thedistributor housing,and position thecap out of the way.

2. Loosen the nut and pull thevacuum line out of the diaphragmassembly.

3. Lift the rotor off the cam.4. Removethe spring clip securing

STATIONARYSUB-PLATE

MOVEABLE

HOUSING

SHAFT

OILER DRIVEPIN-ø4 OIL SEALGEAR

COLLAR PIN

STOP

BREAKER POINTASSEMBLY

CONDENSER

CLAMP

SPRING

SPRING WASHER

FLAT WASHER

LUBRICATING WICK

RETAINER

FIG. i-Typical Dual Advance Distributor

VACUUM CONNECTION

81380-B

PART 9-2-DUAL ADVANCE DISTRIBUTORS 9-23

the diaphragmlink to the movablebreaker plate. Disconnect the diaphragmassemblyfrom the distributor housing. Lift the diaphragmlinkoff the pin and remove the diaphragmassembly.

5. Working from the inside of thedistributor, removethe primary ordistributor-transistorlead wire bypulling it throughthe openingin thedistributor.

6. Remove the two retainingscrews and lift the entire breakerplate assemblyout of the distributorhousing.

7. Lift the lubricating wick out ofthe cam. Using needle nose pliers,removethe camretainerandlift thecamoff the distributor shaft.

8. Lift theupper thrust washeroffthe distributor shaft. Carefully unhook and remove the distributorweight springs. Mark each springand the adjusting bracket to whichit is attached.Lift the weights outof the housing.

DIAPHRAGM AND BREAKERPLATE ASSEMBLY

1. Removethevacuumconnectionandgasket,then removethecalibrating washers,return spring and stop.

2. Removethe retainingscrewandlift the condenserif so equippedoff thebreakerplate Fig. 1.

3. Removethe retainerandwashers securing the movable breakerplate to the stationarysub-plate.

ASSEMBLY

DIAPHRAGM AND BREAKERPLATE ASSEMBLY

1. Install the breaker point assembly on the breakerplate.Positiona new condenserif so equippedand secureit in place with the retaining screw.

2. Install the stop, return springand calibration washers, then position a new gasket on the vacuumconnection. Install and tighten thevacuum connection.

INSTALLATION OFCOMPONENTS

1. Install the weights in thehousing, theninstall thedistributor weightsprings on the adjusting bracketsfrom which they were removed.Install the upperthrust washeron thedistributor shaft.

2. Fill the grooves in the upperportion of the distributor shaft withdistributor cam lubricant. Positionthe camon the distributor shaft andinstall the cam retainer. Apply alight film of distributor cam lubricant to the cam lobes. Install thewick in the cam assembly.Saturatethe wick with SAE lOW engineoil.

3. Position the stationary sub-plate in the distributor. Install oneend of the ground wire under theplate retaining screw closest to thediaphragmmounting flange.

4. Positiontheentirebreakerplate

assembly in the distributor housingand securein place on the sub-plateby installing the washers and retainer. Be sure the protrudingedges of the spring washer arefacing upward.

5. Attach the ground wire to thebreaker point attaching screw farthest from the breakerpoint adjustment slot. Working from inside thedistributor housing,passthe primaryor distributor-transistor lead wireassemblythrough the opening in thedistributor body. From outside thedistributor, pull the wire throughtheopening until the locating stop isflush with the inside of the distributor.

6. Connectthe condenserwire ifso equippedandthe primaryor distributor-transistor lead wire to thebreakerpoints.

7. Position the diaphragmassembly and hook the diaphragm linkover the pin on the breaker plate.Install the diaphragm assembly retaining screws.Securethediaphragmlink with a spring retainer.

8. Adjust the breakerpoint springtension, align the breakerpoints andadjust thebreakerpoint gap. Checkthe breaker point dwell and resistance. Check the centrifugal andvacuum advance refer to "Dis-:tributor Tests".

9. Install the rotor anddistributorcap.

10. Connect the primary or distributor-transistor wir’e.

REMOVAL AND INSTALLATION

REMOVAL

1. On a conventional ignition system, disconnectthe primary wire atthe coil. On a transistor ignitionsystem, disconnect the distributor-transistor lead from the quick disconnect.Disconnect the vacuumadvance line at the distributor. Remove the distributor cap.

2. Scribe a mark on the distributor body and engineblock indicatingtheposition of the body in theblock,andscribe anothermark on thedistributor body indicatingthe positionof the rotor. These marks can beused as guides when installing thedistributor in a correctly timed engine.

3. Remove the distributor holddown cap screw and clamp. Lift thedistributor out of the block.

INSTALLATION

The distributor installation isshownin Fig. 2.

1. If the crankshaft was rotatedwhile the distributor was removedfrom the engine, it will be necessaryto time the engine.Rotatethecrankshaft until No. 1 piston is on TDCafter thecompressionstroke. Alignthe TDC mark on thetiming pointerwith the timing pin on the crankshaft damper.Position the distributor in the block with the rotor atthe No. 1 firing position.

Make sure the oil pump intermediateshaft properly engagesthedistributor shaft. It may be necessary to crank the engine with thestarter, after the distributor drivegearis partially engaged,in order

199

F 1G. 2-DistributorInstallation

to engagethe oil pump intermediate shaft.


Install, but do not tighten, the the mark previously scribed on the coil. On a transistorignition system,retaining clamp and screw. Rotate distributor body, and the markson connectthedistributor-transistorleadthe distributor body counterciock- thedistributorbody andengineblock to the quick disconnect.wise until the breakerpointsarejust in alignment. Install the retaining 5. Check the ignition timing withstarting to open. Tighten the clamp, clamp, a timing light and adjust if neces

2. If the crankshafthasnot been 3. Install the distributor cap. sary. Connectthe vacuum line, androtated, position the distributor in 4. On a conventionalignition sys- check the advancewith the timingthe block with the rotor alignedwith tern, connecttheprimary wire to the light when the engineis accelerated.

MAJOR REPAIR OPERATIONS

BENCH DISASSEMBLY

1. Remove the distributor andplaceit in a vise.

2. Removethe rotor. Removethespring clip securing the diaphragmlink to the movable breaker plate.Disconnectthe diaphragmassemblyfrom the distributorbase.

3. Lift the diaphragmlink off thepin and remove the diaphragmassembly.

4. Disconnectthe primary or distributor-transistorlead wire and thecondenser wire if so equippedfrom the breakerpoint terminal.

5. Working from the inside of thedistributor, remove the primary ordistributor-transistor lead wire bypulling it throughthe opening in thedistributor.

6. Remove the condenser if soequipped.

7. Removethe breaker point assembly.

8. Remove the lubricating wick.Using needlenosepliers, removethecamretainer.

9. Remove the movable breakerplate spring retainerandwashers.

10. Remove the stationary sub-plate retaining screws. Remove thesub-plate,breakerplate and cam asan assembly.

11. Remove the upper thrustwasher.

FIG. 3-Gear PinRemoval or Installation

12. Carefully unhook and removethe distributor weight springs. Markeach spring, bracket and adjustingpost to which it is attached.

13. Removethe weights.14. Remove the distributor cap

clamps.15. If the gear and shaft are to

be used again, mark the gear andshaft so that the pin holes can beeasily aligned for assembly. Removethe gear roll pin Fig. 3, thenremovethe gear Fig. 4.

16. Remove the shaft collar rollpin Fig. 5.

17. Invert thedistributorandplaceit on a support plate in a positionthat will allow the distributor shaftto clear the support plate,and pressthe shaft out of the collar andthedistributor housing Fig. 6.

18. Remove the distributor shaftbushing Fig. 7. Remove the oilsealfrom the distributor housing.

FIG. 5-Collar RetainingPin Removal or Installation

BENCH ASSEMBLY

ORIGINAL ShAFT AND GEAR

1. Oil the new bushing, and installit on the bushing replacertool. Install the bushing Fig. 8. When thetool bottoms againstthe distributorbase, the bushing will be installedto the correctdepth.

2. Burnish the bushing to thepropersize Fig. 9.

3. Oil the shaft and slide it intothe distributor body.

4. Place the collar in position onthe shaft and align the holes in thecollar and shaft, then install a newpin Fig. 10. Install the distributorcap clamps.

5. Check the shaft end play witha feeler gauge placed between the

general ignition system service -...

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