161~-216500 Tach/DwelllVoltmeter

Caution:Read Rutes ForSafe Operefienand Complete

OPERATING INSTRUCTIONS

S-AFETY RULES

TABLE OF CONTENTSPAGE

SOURCES FOR SERVICE INFORMATION..................... ....•. .. 1

WARRANTY STATEMENT ..•..•..•...•...•.........•............•.

RULES FOR.'SAFE AUTOMOTIVE TESTING ..........•..... ; . . . . • . . . . . . 2

GENERAL INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . 3

TACHOMETER CONNECTIONS .•....•.•...••.•...•.•.••••.•.•...• '. 3

G.M. H.E.!. Ignition Systems •••••••.•.••••••••••••••••••••••••••• 3

G.M. Diagnostic Ccnnectors •.•••..••••••••••••••••••• _. • • •• • • • • 3

Ford Ignition Systems .••......•••.••••..•..••.•••••••.•.•••••• -4

Chrysler ond American Motors Ignition Systems ...•..•...•..•....... -4

Tachometer - Engine RPM Measurement Procedure. . . . . • . . . . . . . . . . • 5

BREAKER POINTS RESISTANCE TEST, ...•...•.....•.•........... .- .. , • 5

BREAKER POINTS DWELL TEST AND ADJUSTMENT ...•. '....•. , ..• , .. , . , 5

Dwell Measurements , , , •.......•...... , . , , . , 6

Dwell Adjustments - Bt-eolce.- Poim Syste;";1S••.•••••• _ • _ • _ ••• _ • • • • • • 6

Dwell Reo.dings- Electronic Ignilion Sxstems. • . . • . • . . . . . . . . . . . . . . . . 6

ENGINE TIMING ~ •.... , , . . . • . . . • . . . • • • . . • . . . . . . . . • . . . • . . • . . . . . . 7

Procedure .. " ......•.........•...............•............ , . 7

DWELL VARIATION TEST ........•... , ........•.......• , . • . . . . . . . . 8

IDLE SPEED AND CARBURETOR ADJUSTMENT .......•..... , ..••... , . • 9

VOLTS - PRELIMINARY CHECKS .. , -. . . . . . . . . . . . . . • . . • . . . . • 9

CRANKING VOLTS TEST .•.. : • . . . . . . • . . . • . . • . • . . . . . .. . . . . . • • . . • . . 10

CHARGING SYSTEM VOLTS TEST. • . . • . . • . . . . . . • . . . . . • • . • . . . . . . • • . • 10

POINTS - LOW VOLT AGE TEST ,.................. 10

OTHER APPLICATIONS , .•.• , .•. , . , .. , , , • 11

REPLACEMENT PARTS... .............•..•••.•••.•.....••..••...• 12

ORDERlNG REPAIR PARTS... .• .• • •• •• ••••• •.•. .••• . •••• • 'BACK COVER

IMPORTANTThe information in this manual will serve as a general guide for engine tune·up and charging system tests and adjustments.

CONSULT THE VEHICLE SERVICE MANUAL FOR SPECIFIC TUNE·UP INFORMA·TION AND TEST PROCEDURES. ALWAYS FOLLOW THE MANUFACTURER'SSPECIFICAnONS AND TEST PROCEDURES FOR ADJUSTING DWELL ANGLE,IDLf SPEED sa :::> CHARGING SYSTEM OUTPUT. ESPEOAllY VEHIClES WITHJ.\Oi)ERt-. 2....=ciRO iIe IGNITION AND EJ.\1SS1O CONTROLS. DO NOTATTEMPT TO SERVICE VEHICLE WITHOUT MANUFACTURER'S INSTRUCTIONS.

SOURCES FOR SERVICE INFORMATIONThe following is a lis! of publishers who have service manuals 10< your specific vehicle at nominal cost. Write to themfor availability and prices, specifying the make, style. and IJlOdd year of your vehicle.

A. E. A. Tune-Up Cha.....k~ 3.eonc:.sm.IJO' ". 22Do SL s....w.e 1C:Execu-ive Pfazo &ilo insOak Brook.1lGnois 60521

fl:::i:;::Jr's -_""""=- ie=:c::K ~:!!: s._:_ s-"",.

Sew-y~ .._ ::n. l'Xl~

Notional Service Ooio BookNotional Automotive""Servlce, Inc ......

Dill. Glenn Mitchell Manuals, Inc.

Soxl~5=:li=g:- Ccih:r..io 921 10

Chilton's Auto Repair Manuel

Chlron Compony

.5X- == ~ S::ress

GMDio;;~= ~=&=I:;.::i

GM DR Manucl-eoc_=P.O. Sox 1185

~~"5=roi:= ::~Oep1.~~A.Ye.

r

Scuthheld, MichisClD ~ ~......." ~ 48015

- - b::=l: :xa _ e:J

=c, x.xU""5:

90-DA Y WARRANTY

[

LTHIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS

WHICH VARY FROM STATE TO STATE.

SEARS, ROEBUCK AND CO.

DEPARTMENT 698/731A

SEARS TOWER

CHICAGO, IL 60684

IF, WITHIN 90 DAYS FROM THE DATE OF PURCHASE, THIS AUTOMOTIVE TEST INSTRUMENT FAILS

DUE TO A DEFEO IN MATERIAL OR WORKMANSHIP, RETURN IT TO THE NEAREST SEARS STORE

THROUGHOUTTHE UNITED STATES, AND SEARS WILL REPAIR OR REPLACE IT, FREE OF CHARGE.

4. When operating any test instrument from onauxiliary batlery, connect a jumper wire betweenthe negative terminal of the auxiliary batteryand chassis ground on the vehicle under test fornegative ground systems. for posirve grounOsystems, connect the jumper wire to the positiveterminal of the auxiliary battery and chassisgroun-d on the vehicle. When working in a gar-age or other enclosed area, auxiliary batteryshould be located at least 18 inches a bove thefloor to minimize the possibility of sparks ignitinggasoline vapors and causing on explosion.

RULESFOR SAFE AUTOMOTIVE TESTINGREAD CAREFULLY

1. Read this Owner's Manual and these Rules forSafe Automotive Testing carefully. Failure tofollow instructions and safety rules could result inserious bodily injury c nd Zor damage to theinstrument.

2. Before starting the engine, set the parking brokeand place gear selector in NEUTRALon standardtransmissions or PARKon automatic transmission.

3. The carbon monoxide in exhaust gas is highlytoxic. To ovoid asphyxiation, always operatevehicle in a well-ventilated area. If vehicle is inon enclosed area, exhaust should be routeddirectly to the outside via leakproof exhausthose..

5. An automobile battery is capable of producingvery high currents. Therefore, exercise reason-able core when working near the battery toovoid electrical connections through tools,wristwatch, etc.

6. Avoid contact with battery electrolyte. It can eatholes in clothing, burn skin and couse permanentdamage to eyes. Always wear splash proofsafety goggles when working around the bot-tery. If battery electrolyte is splashed in the eyesor on skin, immediately flush the affected areafor 15 minutes with large quantities of deanwater. In ccse of eye contact, seek medical aid.

7. The gases generated by a charging battery arehighly explosive. Do not smoke or permit flameor spark to occur near a battery at any time,particularly when it is charging. Any room or

comportment containing charging batteriesshould be well ventilated to prevent accumulo--tion of explosive gases. To ovoid sparks, do notdisturb the battery charger connections whilebattery is charging, and always turn charger offbefore disconnecting the battery clips. Whenremoving Of reconnecting battery cables, makesure ignition swiIdt and all accessories arefumed off_

8_ Never odd acid to a battery once the batteryhas been placed in service. Doing so may resultin dangerous spattering of electrolyte.

9. Keep hands, hair, necktie, loose clothing and testleads well away from fan blade, fan belt, powersteering belt, air conditioner belt and other mov-ing engine ports, as serious injury could resultfrom entanglement.

10_ Do no1 cuch boo exb£:us ~, ... dieter orhigh-vottage sparle plug and coil terminals. "" '''~ --~-Spark voltages are not normally lethal but oninvoluntary jerk of the hands or arms caused byelectrical shock may result in injury.

11. Never look- directly into carburetor throat whileengine is cranking or running. A sudden backfirecan couse serious burns.

12. To ovoid the possibility of a flash fire, do notsmoke or permit flame or spark to occur nearcarburetor, fuel line, fuel filter, fuel pump orother potential sources of spilled gasoline orgasoline vapors.

13. Never remove radiator cop while the engine ishot. Hot coolant escaping under pressure cancause serious bums..

14_ The jock supplied with the vehicle should be usedon1y for changing wheels. Never crowl under coror run engine while vehicle is on [ock.

15. When making electrical test connections to thevehicle, do not use the carburetor or other fuelsystem components as a ground connection, as aspark could ignite the gasoline vapors and cousea fire or on explosion.'-

litL- ~

l 2

,

I~

GENE~AL INSTRUCTIONSConnections For RPM, Dw.ell, Volts and Points TestsConnect the GREEN Clip to the distributor terminalon the. ign'i,tion coil or TACH (tachometer) terminalon electronic ignition systems to measure RPM,DWElL or POINTS condition.

Connect the GREEN clip to the battery Positive (+)terminaL to measure STARTINGAND CHARGINGVOLTAGES.Connect the BLACKclip to a secure ground connec-tion on the engine, frame, OT alternator brocket osshown in Figure 1_The Bl.AOCdip should !be the,last cennecflen nta.de, and ihe-fil'rlio bedisconnected.

rI CAU.TION!

Avoid connecting directly to the BatteryNegative Terminal in t~e event that hydrogengases are present which could explode fromsparking connections.

--

CONNECTIONS FOR RPM, 0 VB!,.. VOlTSAND POINTS TESTS

FIGURE'l

TACHOMETER CONNECTIONSNOTE: This analyzer is not designed to be used on

capacitive-discharge electronic ignition.systems to measure RPM and DWELL. If 50

used, it may indicate incorrect engine speedond dwell readings or may cause theenqine to-run roughly or stall: However,typically; o'hJ,ya very few import vehicles'use th.is.type system. If you ere in doubt asto the' type system .you have, refer to yourvehicle inanual.

TACHOMETER CONNECTIONS TO;GENJRAl MOTORS DelCO HiGH ENERGY

IGNITION SYSTEMS'On 4 cylinder and in-fine 6 cylinder engines. with '0.

separate coil; connect the GREEN clip to the openTACH terminal as indicated in Fig. 2. On the inte-grllli coil V-B or Y:6 HEI Systems, slide the adapter'onto the TACH terminal as shown in Fig. 3. Thenconnect the GREEN clip to the adopter.

The BLACKclip must be connected to a secureground connection as shown in Figure 1.

onco HEl WITH SE?ARA TE COIL4 Cyfin& and LHine 6 Cylinder Cars

~2

HEI ADAPTERINCLUDED

.

-

DELCO HEI WITH INTEGRALCOILY-6 and V-8 HEI SYSTEMS

FIGURE 3

TACHOMETER CONNECTIONS TOGENERAl MOTORS CARS WITH DIAGNOSTIC

CONNECTOR AND DELCO HIGH ENERGYIGNITION SYSTEMS '. .

To make RPM testS;.locate.the Engine ElectricalDiagnostic ConnectorIusuolly neor theleft frontIender). Open the cover and insert the cdcpter in

3

socket N~. 6 as shown in Figure 4. Connect theGREEN clip to the spade terminal adapter.

The BLACK clip must be connected to secure groundconnection as shown in Figure 1.

SPADE TERMINALADAPTER

TACHOMETER CONNECTIONS TO GENERALMOTORS CARS WITH DIAGNOSTIC CONNECTORAND DELCO HIGH ENERGY IGNITION SYSTEMS

FIGURE 4

TACHOMETER CONNECTIONS TO FORDELECTRONIC IGNITION SYSTEMS AND

TACHOMETER/DWELL CONNECTIONS TOFORD BREAKER POINTS IGNITION SYSTEMS

FORD ELECTRONIC IGNITION SYSTEMS

On 1974 Ford Electronic ignition systems, connect asshown in Figure 6, using the Ford adapter asshown.

On 1975 Ford transistor ignition systems, connectthe GREEN clip to the wire terminal on the "DEC"or "TACH" side of the coil as shown in Figure 5.

Connect the BLACK clip to a secure ground connec-tion as shown in Figure 1.

1975 AND LATER FORD ELECTRONICIGNITION' SYSTEMS

FIGURE 5

4

FORD BREAKER-POINTS IGNITION SYSTEMS

Lift the distributor terminal and slide the FORDadapter clip in place as shown in Figure 6, thenpush the terminal down on it. Remove when thetests are finished.

Connect the BLACK clip to a secure ground connec-tion as shown in Figure 1.

ADAPTERINCLUDED~

1974 FORD EtECTRONIC AND ALLBREAKER-POINT IGNITION SYSTEMS

FIGURE 6

TACHOMETCR CONNECTIONS TO CHRYSLERAND

AMERICAN MOTORS IGNITION SYSTEMS(TACH/DWELL TO BREAKER-POINTS SYSTEMS

AND TACH TO ELECTRONIC SYSTEMS)Connect the GREEN lead to the negative terminalof the ignition coil as shown in FIGURE 7.

Connect the BLACK clip to a secure ground connec-tion as shown in FIGURE 1.

CHRYSLERAND AMERICAN MOTORSCONVENTIONAL AND TRANSISTOR

IGNITION SYSTEMS

FIGURE 7

TACHOMETER - ENGINE RPM MEASUREMENTPROCEDURE -Connect the BLACKmid GREEN leads of the

~ TACH/ DWELL/VOLTMETER as described on pages3-and 4. for tlie pcrticulcr engine you aretrouble-shooting. .-

Place the FUNCTION SELECTOR Switch to the RPMposition.

Start the engine and operate it ot idle RPM. Asillustrated in Figure 1, observe the upper RPM scale(0-20) for 8 cylinder engines, and the lower RPMscale (0-25) foe 6 cyfinder e.ml..)r.es. Multiply theindicated nember by 100 to obtain me cdua'en§ine speed in RPM.

NOTE: For 4 Gylinder engine_s, multiply the 8cylinder scole by 200 to obtain the cctuc]engine speed in RPM.

Engine DWELL and Timing may now be performedat the engine 'speed s-pecified in your vehicleowner's manual.

BREAKER POINTS RESISTANCE TEST(This procedure is not for eleetrenic ignitionsystems).During engine tune-ups OF repoir, this test shoufdbe done before adjusting the engine timing (thot

__ iSi,changlngjbe aavanEe or retcrd-of the distribu-tor) or breaker-points DWELL time. -

NOTE: Remove the distributor cap and inspectthe breaker points.. Property adjusredbreaker points ~ ~ gray m dcrduring normal use. Irir.ey are ~=.blackened 01" piHed, • ey mrre-exceeGootheir normal life, or excessive ClJTTemhasbeen present in the primary circuit, Check

.. Iorexcessively low coil resistance (shortedt~ms)-Iow ballast resistor value and highbattery voltage while the engine is cun-ning. Correct any of the above problems,replace the breaker points and proceed 10the next step. If the breoker points poss thevis-ual inspection fest, also proceed to thenext ste-p~ -. . _. __=

1. The engine must be OFF. The test leads must beconnected as shown in Figure 1.; GREEN clip to"DIST./1

·2. Set the FUNCTION SELECTOR knob to the VOLTSposition.

3. Replace the distributor cap and REMOVE THE.HiGH TENSION LEAD FROM THE CENTER OFTHE DISTRIBUTOR CAP AND GROUt'lD" IT BYCONNEGTfNG THE LOOSE END TO THE ENGINE

- OR FRAME ..

NOTE: When testing a vehicle with dual points,alternately block one set of points open

with a piece of insulating 'material whilethe other set is being tested:

4. TURN THE IGNlflON KEYON. If the mete-r readsnear full scale (right), the points are open asshown in Figure 8-. Cronk the engine a fractionof a revolution-ot a time until the meter reads inthe left hand area of the scale, as shown inFigure 8. The points are now closed.

5. TEST RESULTS

POINTSOPEN

POINTS OK

FIGURE 8

fiGURE '9

-:::~ ~ indicates in the DEFECTIVE AREA when~~c:!'edmed, as shown In Figure 9, the~ -q ce defective or the following faults mays:xm:

• i'bor Cis:iihufor ground..' i'oor a::o'"'-edion on Ihe primary lead from the

disfri'hu.ror ~o ~ue ignition coil.• Defective distributor pigtoilleod.• Misaligned poinis• Poor points/plate ground inside distributor.

Correct-the defeEt and r_~BeaUhee fest.-

BREAKER-POINTS-DWELL TESTAND ADJUSTMENT

NOTE: This test and adjustment procedure isperformed on cars with conventionalbreaker-points. ignition systems endtransistorized ignition systems with breokerpoints such as some ofter-rncrket units. Thisprocedure is not to be used on vehiclesequipped with vorious all-electronic ignitio.hsystems or copccitive-dischorqe systems.

5

Before performing the DWELL TEST and ADJUST-MENT procedure, read the vehicle owner's manualor-the engine compartment decal to determinewhat should be done with the vacuum hose con-nected to the distributor and the advance/retordsolenoids. Most often, the vacuum hose must bedisconnected from the distributor as shown inFigure 11 and the end plugged with a golf "lee"or plug.

8

RPM AND DWELL SCALES

FIGURE 10

DWELL MEASUREMENTSRefer to Figure 10 for identification of the RPM andDWELL Scales. Set the FUNCTION SELECTORSWITCH to RPM. Start the engine and operate it atthe specified idle RPM. Set the FUNCTION SELEC-TOR SWITCH to DWElL Compare the meter dwell

,.- angle reading with the mcrrufocturer's specific'l"ionfor the engine. If the dwell reading is higher orlower than the manufacturer's specification, adjustthe distributor points as illustrated below and des-cribed in the following sections.

For 4 cylinder engines, multiply the ,8 cylinder RPMscale by 200 and the 8 cylinder Dwell scale by 2.

DISTRIBUTOR VACUUM HOSE CONNECTION

FIGURE 11

DWEU ADJUSTMENT-CONVENTIONAL BREAKER POINT SYSTEMS

On GM distributors with a small metal slide cover,Ijft the- cover and lnsert a !JailAllen wrench in theadjusting screw socket and adjust the dwell by turn-ing the wrench, es snown in Figure J 2.On Ford, Chrysler, American Motors and otherdistributors not equipped with a small metal accessslide cover, perform the following steps whilereferring to Fjgure 13.

1. Remove coil wire from center tower of distributorcap and ground' the wire by connecting theloose end to the engine or frame.

2. Remove the distributor cap and rotor.

3_ Conned a remote starter switch to the vehicle orhave on assistant crank the engine for you.

4. With ignition switch ON and engine crankingobserve re-oding on the Dwell scale.

1/8" ALLENWRENCH

TYPICAL GENERAL MOTORSBREAKER-POINTS DISTRIBUTOR

FIGURE 12

5. To adjust Dwell, loosen the locking screw slightlyand adjust the point gap with a feeler gaugeaccording to the procedure outlined in the vehi·cle's service manual. After adjustment, tightenJacking screw, and recheck dwell while crankingengine. Repeat procedure if necessary.(FIG. 13).

6. Reassemble distributor and recheck dwell read-ing with engine operating at idle speed.

Repeat steps 5 and 6 if necessary.

DWELL READINGS-ELECTRONIC AND TRANSISTOR IGNITIONS

Due to the vast array of. electronic ignition andengine control systems being used on late model

6

cars, it is essential that specific service informationfor the vehicle under teste-be obtained. Althoughdwell angle is not adjustable-on electronic systems,the reading obtained is.irnportcnt and should bewithin themanufacturer's specified limits. If it is not,consult the monujocturer/s ~hop manuals for diag-nostic procedures and possHJ'le componentreplacement instructions.

To measure the DWELL angle on electronic ignitionsystems, set the FUNCTION SELECTOR SWITCH toRPM, Start the engine and operate it ot the speci-fied idle RPM. Set the fUNCTION SElECTORSWITCH to DWELL Con:.pore me Jt>et-d dwell anglere.adio_g- with the manufacturer's specificotions forthe engine. If the reading'is higher or lower thanthe recommended value; consultthe owner'smanual, diagnostic procedures" for your particularvehicle to correct the problem,

TYPICAL FORD, CHRYSLER, ANDAMERICAN MOTORS BREAKER·POINT

DISTRIBUTORS

FIGURE 13

ENGINE TIMINGThe engine should be timed at each tune-up afterthe dwell adjustment, but before idle speed and

_mixture adjustments are made.

Check your owners manual for the location of thetiming marks and the timing specifications. Refer toFigu_re 14. Then use a timing jight to time the

engine to specifications.

Connect the Timing-Light to the battery end enginein accordance with the instructions .supplied withthe instrument or as shown in F-igure'15. '

Timing 'lights recommended for best service-ere theSears Craftsman bright chrome Models 2194(advance timing light)' and 2134 - both accurateto 8000 RPM.

The popular and reliable Sears models 21174 and21684 timing lights are accurate to 6000 and 4000RPM respectively. For safe operation, all Sears tim-ing Iigbts inductively damp around tbe spark plugwire without need for disconnecting high volfagewires or exposing spark plug caps. Visit your locclSears retail or catalog store for these products.

PRELIMINARY1. Check the distributor dwell angle and adjust to

the manufacturer's specifications, if necessary,before timing the engine.

Z. Clean the dirt f..-om_lhe timing marks.

3_ Disconnect the vacuum advance hose from thedistributor and seal the end of the hose withtape or a plug os shown in figure 16_

7

PROCEDUREI", St~_rt~tlJ_~.cengi@.l91~d ~!Iow i_t..,!~wqr~ _"'_P' '10.",..,,,,,,,,~>..-2, After the engine is warm, operate it at idling

speed or the RPM specified in the vehiclemruwaJ.

3. Aim ihe Ji3ng light at the timing marks, press'lie S'i!ri:dt 0 operate the timing light and~!;re liming mark. The position of the timeCg =dt ::;:11,8 ogree with the manufacturer's~ If ii' does not, reset the timing as~

4_ lcosenti1eGisiriDutor hold-down clomp JUSTenougn to pernm rotating the distributor bodyby hand os shown in figure 16.

5. Slowly tum me distributor in the correct directionas shown in Figure 17:a. Against the roto;'r-ofation to advance the

fiming.b. With the rotor rotation to retard the timing.

6, Repeat Step 3.

7. When the specified mark is in line with the tim-ing line, securely tighten the distributor hold-down clamp and recheck timing,

8. Check the idle RPM after the engine is timedand re-adjust to the manufacturer's s-pecificationif necessary.

9. Remove the plug from ·the vacuum, hose .cndattach it to the distributordiophrqqmconnection.

VARIOUS TIMING MARK CONFIGURATIONS

FIGURE 14

TYPICAL TIMING LIGHT USAGE

FIGURE 15

~il

ROTOR ROTATION........

ROTOR ROT ATION,_.

ENGINE TIMING ADJUSTMENT PROCEDURE

FIGURE 17

DWELL VARIATION TESTRecc e ~s ~_'C """ engIDe comportmentdecal and follow the instructio_ns regarding vacuumline or advance-retard solenoid connections whenchecking DWELL angle. Usually, the vacuum hosemust be disconnected from the distributor andplugged as shown in Figure 20.

Increase the engine speed from idle to about 1500RPM an'd note the dwell angle. Re.turn the enginespeed to idle and again note the dwell angle.

If the difference between the two dwell anglereadings is more than 3 degrees, check for exces-sive wear in the breaker point plate and couplingsor excessive wear in the distributor shaft gear andbushings.

DWEll VARIATION

FIGURE 18

8

IDLE SPEED ANDCARBURETOR ADJUSTMENT

1. The engine should be at normal operatingtemperature for this test. Many cars built in1970 and later have idle mixture screw limitercaps that restrict adjustment. On these cars thecarburetor should be adjusted according to theprocedure in the manufacturer's service manual.

2. Shut the engine off and conned the test leadsas shown in FIGURE 1 or for Bectronic IgnitionSystems and late model COI"5, see FIGURES 1,2,3, 4, 5, 6, and 7. Set the fUNCTION SElfCTORKnob to the RPM position.

3. Consult the manufacturer's service manuaHorthe location of the idle speed adjusting screwand the idle mixture adjusting screw (or screws).Make idle speed and mixture adjustments.according to the procedure outlined in the ser-vice manual or as specified on the decal in theengine compartment.

Figure 19 illustrates typical locations of the idlespeed and idle mixture screws on single andmulti-barrel carburetors.

TYPICAL IDLE SPEED ANDMIXTURE SCREW LOCATIONS

FIGURE 19

SINGLE BARREL CARBURETOR

DOUBLE BARREL CARBURETOR

4. Start the engine and turn the idle speed screwuntil specified idle speed is indicated.

5. On engines without exhaust emission control sys-tems, turn the idle mixture screw in (lean) untilthe idle speed starts to decrease, then turn itbock out (rich) just until the idle speed reaches amaximum. Further richening past this point willonly waste fuel. This should be' done slowly toallow engine speed to stabilize.

6. On multi-barrel carburetors, repeat this proce-dure on each idle mixture screw until the highestidle speed and smoothesf operation is obtained.If the engine idle speed is now higher than themanufacturer's specification, turn the idle speedadjustment screw until the specified idle speed isindicated and readjust the mixture screws withthe above procedure. .

7. NOTE: On engines equipped with exhaust emis-sion control systems, air injection pumps and pos-itive crankcase ventilation, refer to the decal inthe engine comportment or the owners manualfor idle adjustment sp_ecifications.

o\'_PLUG END OF

VACUUM LINEDISTRIBUTOR VACUUM HOSE CONNECTION

FIGURE 20

VOL TS-PRELIMINARY CHECKSThe VOLTS switch position is used to test the crank-ing and charging volts in the vehicle.

CONSULT THE OPERATING MANUAL OF THE JI' •.VEHICLE BEING TESTED FOR SPECIFIC VOLT-AGES AND TEST PROCEDURES:

The following information will serve as a generalguide for making charging system tests.

Before making VOLTS tests:

Check the fan belt - it should be tensionedaccording to the manufacturer's-specifications.

9

Check the generator or alternator pulley andmounting bolts. They should be tight. -

Make sure that the charging system wiring and thebattery cables are in good condition and that con-nections are tight. Make sure the battery is deanand that the liquid level in each cell is above theplates.

The engine and all parts of the charging systemshould be at normal operating temperoturs beforemaking any electrical tests. If the engine is cold,operate the engine at idle speed for at least 15minutes before making any tests.

CRANKING VOLTS TEST1. To prevent the engine from starting while crank-

ing, remove the high tension lead from the cen-ter of the distributor cap and ground it by con-necting the loose end to the engine or frame onsystems with a sepa rate coil.

For systems with integral coil as shown in Figure3, disconnect the primary wire from the "BAT"terminal on the distributor cop. CAUTION: TheTACHOMETER terminal must NEVER be con-nected to ground at the distributor cap asdamage to the distributor-ignition module canresult.

For systems with on electrical diagnostic connec-tor as shown in Figure 4, insert the GM diagnos-tic spade terminal adapter in terminal No.6and connect a jumper wire between this termi-nal and a secure ground on the engine orframe. Do not connect the TACH terminal at thedistributor to ground as damage to thedistributor-ignition module can result.

'2. Connect the test leads 'as shown in FIG. 1:GREEN clip to the Battery POS. (+). Set theFUNCTION SELECTOR SWITCH to VOLTS.

3. Operate the starier for 10 seconds and observethe cra nking voltage on the 0- 16 volts scale asshown in Figure 21. A steady reading of morethan 9.6 volts indicates that the battery, cablesand starter system are in good condition.

CRANKING AND CHARGING VOLTS TESTS

FIGURE 21

4. A reading below 9.6 volts could be caused by abattery that is defective or not fully charged.Fully charge the battery and repeat the test. Ifth.e reading is still below 9.6 volts, either thebattery or starter is defective.

5. A fluctuating voltage reading is indicative of adefect in the starter or battery or in the battery-starter wiring circuit. Refer to AGURE 23, LOWVOLTAGE TEST, for troubleshooting voltagedrops in the battery-starter wiring circuit.Replace or repair any defective parts asrequired to restore cranking system to properoperation.

6. To restart the engine, replace the high tensionlead to the center of the distributor cop, replacethe wire to the "BAr' terminal of the integralcoil distributor, or remove the jumper wire fromterminal 6 of the diagnostic connector.

CHARGING SYSTEM VOLTS TEST1. Connect the test leads as shown in Figure 1;

GREEN clip to the Battery POS. (+) terminal. Setthe FUNCTION SELECTOR switch to the VOLTSposition.

2. Start the engine. Allow it to run for at least 5minutes at 1500 to 2000 RPM. Observe therec.ciog on -he 0-16 ...oe sec e cs sbown inFIGURE 21. The reo ding should gradually risefrom about 12.5 volts before starting to 13.2volts to 15.2 volts at the end of the 5 minutes,with or without the headlights and blower motoron.

Readings lower than 13.2 indicate either a wornout battery, defective generator or alternator ordefective or improperly adjusted voltage regulator.

Readings above 15.2 are indicative of a defectiveor improperly adjusted voltage regulator.

Replace, repair or adjust the defective port asrequired.

POINTS - LOW VOLT AGE TESTThe POINTS scale is also a 0-2 volt range as shownin Figure 22_ This scale is useful for checking volt-age drops in the vehicle's electrical system.

Set the FUNCTION SElECTOR S~ITCH to the VOLTSposition.

Corroded or loose connections and frayed orbroken cables can couse hard starting. To test forthese conditions, refer to Figure 23 and alternatelyconnect the clips between 1 and 2, 2 and 3,4 and5,5 and 6, 6 and 7, 7 and B with the starter turn-ing. During this test, no reading should be higherthan .2 volt. If a reading higher than .2 volt isobserved during any of these tests, check the coble

10

or connections involved, clean and tighten the con-nections and replace the cables or solenoid whennecessary.

If the meter reads to the left of zero during any ofthe. above tests, reverse the position of the GREENand BLACK clips.

OTHER APPLICATIONS.Foreign Cars

Due to the vast array of different ignition systemsfound on import cars, it is not possible to cover allapplications in a manual of this type. You arerecommended to purchase a service manual foryour particular vehicle and follow the proceduresoutlined by the vehicle manufacturers.8 106

.Mazda Rotary EngineThe Mazda has two separate sets of breaker pointsand two ignition coils. Each set of points must beadjusted individually for dwell angle, normally 55°to 57°. (Consult your vehicle service manual forexact specifications.)

Readings for both Tach and Dwell are the same asfor a 4 cylinder engine. When using the model2165 TACH/DWELL/VOLTMETER, multiply the 8cylinder Tachometer scale reading by 200 to obtainthe actual engine speed in RPM. To measure dwellangle, multiply the 8 cylinder Dwell Angle scalereading by 2.

o

for.: cyl engineDouble 8 cyl sccle

POINTS AND VOLTAGE SCALES

FIGURE 22

LOW VOLTAGE TESTFIGURE 23

11

REPLACEMENT PARTS

FIGURE 24

KEY NO. PART NO. DESCRIPTION

1 400·857 Case, bottom

2 270·117 Screw, Case Self-top. #6·20 x 1"

3 38·726 Cable Assembly, Green and BlackClip

4 450·133 Cop, Glamour

5 10()()..425 Ignition Adopter Kit

* 2·1682 InsiructionManual (not illustrated)

12

FREQUENTLY USED TUNE-UP.INFQRMATIQN

IDLE -DWELL SEARS SPARKVEHICLE- ~

TlMING- TUNE-UP PLl::1GRPM - ANG,lE -

KIT r, , '- T-YI'E- 0

-,

"":>0, = "" - - ~-- ~- -: c

-[F-

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r notesr~/'/

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ISears Iownersmanual

MODEL NO.161.216500

HOW TO ORDERSPARE PARTS

,;

IS::rtr;SOlid State Electronic

Tach / Dwell / Voltmeter

Now that you have purchased your Toch/Dwell/Voltmeter,should a need ever exist for repair ports or service, simplycontact any Sears, Roebuck and Co. store. Be sure to pro-vide all pertinent facts when you call or visit.

The model number of your Tach/Dwell/Voltmeter can befound on the front of the instrument.

WHEN ORDERING REPAIRPARTS, ALWAYS GIVE THE FOl·lOWING INFORMATION;

PART NUMBER

PART DESCRIPTION

MODEL NUMBER

NAME OF ITEM

All parts listed may be ordered from any Seors ServiceCenter and most Sears stores.

If the parts you need are not stocked locally, your orderwill be electronically transmitted to a Sears Repair PartsDistribution Center for handling.

SEARS,ROEBUCK AND CO. U.S.A.CHICAGO,ILLINOIS 60684

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