EXJ_8D99 jeep xj service manual

7/29/2019 EXJ_8D99 jeep xj service manual

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IGNITION SYSTEM

CONTENTS

page page

GENERAL INFORMATIONINTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 1

DESCRIPTION AND OPERATIONAUTOMATIC SHUTDOWN (ASD) RELAY . . . . . . 3CAMSHAFT POSITION SENSOR . . . . . . . . . . . . 3CRANKSHAFT POSITION SENSOR . . . . . . . . . . 3DISTRIBUTOR . . . . . . . . . . . . . . . . . . . . . . . . . . 2

ENGINE COOLANT TEMPERATURESENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

IGNITION COIL . . . . . . . . . . . . . . . . . . . . . . . . . 3IGNITION SWITCH AND KEY LOCK

CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . . . 4IGNITION SYSTEM . . . . . . . . . . . . . . . . . . . . . . 1INTAKE MANIFOLD AIR TEMPERATURE

SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

MANIFOLD ABSOLUTE PRESSURE (MAP)SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

POWERTRAIN CONTROL MODULE . . . . . . . . . . 2SPARK PLUG CABLES . . . . . . . . . . . . . . . . . . . 2

SPARK PLUGS . . . . . . . . . . . . . . . . . . . . . . . . . 2THROTTLE POSITION SENSOR . . . . . . . . . . . . 4

DIAGNOSIS AND TESTINGAUTOMATIC SHUTDOWN

(ASD) RELAY TEST . . . . . . . . . . . . . . . . . . . . 4

CAMSHAFT POSITION SENSOR . . . . . . . . . . . . 8CRANKSHAFT POSITION SENSOR . . . . . . . . . . 7DISTRIBUTOR CAP . . . . . . . . . . . . . . . . . . . . . . 7DISTRIBUTOR ROTOR . . . . . . . . . . . . . . . . . . . 7

ENGINE COOLANT TEMPERATURESENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

FAILURE TO START TEST . . . . . . . . . . . . . . . . . 6IGNITION COIL TEST . . . . . . . . . . . . . . . . . . . . . 5

IGNITION TIMING . . . . . . . . . . . . . . . . . . . . . . . 7INTAKE MANIFOLD AIR TEMPERATURE

SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8MAP SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . 7

SPARK PLUG CABLES . . . . . . . . . . . . . . . . . . . 8SPARK PLUG CONDITIONS . . . . . . . . . . . . . . . 9TESTING FOR SPARK AT COIL . . . . . . . . . . . . . 4

REMOVAL AND INSTALLATIONAUTOMATIC SHUTDOWN (ASD) RELAY . . . . . 13

CAMSHAFT POSITION SENSOR . . . . . . . . . . . 14CRANKSHAFT POSITION SENSOR . . . . . . . . . 13DISTRIBUTOR . . . . . . . . . . . . . . . . . . . . . . . . . 15ENGINE COOLANT TEMPERATURE

SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15IGNITION COIL . . . . . . . . . . . . . . . . . . . . . . . . 12IGNITION SWITCH AND KEY CYLINDER . . . . . 18INTAKE MANIFOLD AIR TEMPERATURE

SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15MANIFOLD ABSOLUTE PRESSURE (MAP)

SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15POWERTRAIN CONTROL MODULE (PCM) . . . 18

SHIFTER/IGNITION INTERLOCK . . . . . . . . . . . 20SPARK PLUG CABLES . . . . . . . . . . . . . . . . . . . 11SPARK PLUGS . . . . . . . . . . . . . . . . . . . . . . . . 12THROTTLE POSITION SENSOR . . . . . . . . . . . 15

SPECIFICATIONS

ENGINE FIRING ORDER2.5L 4-CYLINDERENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

ENGINE FIRING ORDER4.0L 6-CYLINDERENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

IGNITION COIL RESISTANCE . . . . . . . . . . . . . 21IGNITION TIMING . . . . . . . . . . . . . . . . . . . . . . 20SPARK PLUG CABLE RESISTANCE . . . . . . . . 21SPARK PLUGS . . . . . . . . . . . . . . . . . . . . . . . . 21

TORQUE CHART . . . . . . . . . . . . . . . . . . . . . . . 21VECI LABEL . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

GENERAL INFORMATION

INTRODUCTIONThis group describes the ignition systems for both

the 2.5L 4cylinder a nd the 4.0L 6cylinder engines.

O n B o a r d D i a g n os t ics i s d es cr i bed i n G r o up 25,

Emission Control Systems.

Gr o u p 0 , L u br ica t i o n a n d M a i n t e n a n ce , c on t a i n s

general maintenance information (in t ime or mileage

i n t e rv a l s ) f o r i g n it i on r e la t e d i t em s . Th e O w n e r s

M a n u a l a l s o c on t a i n s m a i n t e n a n c e i n f or m a t i o n .

DESCRIPTION AND OPERATION

IGNITION SYSTEMThe ignition systems used on the 2.5L 4cylinder

a n d t h e 4 .0 L 6 c y l i n d e r e n g i n e a r e ba s i c a l l y i d e n t i -

cal . Similari t ies and differences between the systems

will be discussed.

The ignition system is controlled by the powertra in

control module (PCM) on al l engines.

The ignition system consists of:

S p a r k P l ug s

Ignition Coil

XJ IGNITION SYSTEM 8D - 1


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Secondary Ignition Cables

Distributor (contains rotor a nd cam shaft position

sensor)

Powertrain Control Module (PCM)

C r a n k s h a f t P o s it i on , C a m s h a f t P o s it i on , Th r ot -

tle Position and MAP Sensors

POWERTRAIN CONTROL MODULETh e P o w e r t r a i n C on t r o l M od u l e (P C M ) i s l oca t e d

in the engine compartment (Fig. 1).

The ignition system is controlled by the PCM.

NOTE: Base ignition timing by rotation of distribu-tor is not adjustable.

The PCM opens and closes the ignition coil ground

ci r cu i t t o op er a t e t h e i g n it i on coi l. Th i s i s d on e t o

a d ju st ig nit ion t im in g, b ot h in it ia l (ba s e) a n d

a d v a n c e, a n d f or ch a n g i n g e n gi n e o pe r a t i n g con d i -

tions.

The amount of electronic spark adva nce provided

b y t h e P C M i s d et er m in ed b y f iv e i npu t f a ct or s:

engine coolant temperature, engine rpm, intake man-

i f ol d t e m pe r a t u r e , m a n i f ol d a bs ol u t e p r es s u r e a n d

throttle position.

DISTRIBUTOR

Al l e n g in e s a r e e q u i pp ed w i t h a ca m s h a f t d r i ve nmechanical distributor containing a shaft driven dis-

t r i bu t o r r o t o r . A l l d i s t r i bu t o r s a r e e q u i p p e d w i t h a n

internal camshaft position (fuel sync) sensor (Fig. 2).

This sensor provides fuel injection synchronization

and cylinder identification.

Th e d i s t r ibu t or s on bot h t h e 2.5L 4-cy l in d e r a n d

the 4.0L-6 cylinder engines do not have buil t in cen-

t r i fu g a l or v a cu u m a s s is t ed a d v a n ce . B a s e i gn i t ion

t i m in g a n d a l l t i m in g a d v a n ce i s c on t r ol le d b y t h e

powertra in control module (P CM). B ecause ignition

timing is controlled by the PCM, base ignition tim-ing is not adjustable on any of these engines.

The distributor is locked in place by a fork with a

slot located on the distributor housing base. The dis-

tributor holddown clamp bolt passes through t his slot

w h e n i n s t a l l ed . B e c a u s e t h e d i st r i bu t or p os i t ion i s

locked when instal led, i ts rotational position can not

be ch a n g e d . Do not attempt to modify the dis-tributor housing to get distributor rotation.Distributor position will have no effect on igni-tion timing. The position of the distributor willdetermine fuel synchronization only.

Al l d is t r ib u t or s con t a i n a n i n t er n a l oi l s ea l t h a t

p r ev en t s oi l f r om e n t er i n g t h e d i st r i bu t or h ou s in g .The seal is not serviceable.

SPARK PLUGSAll engines use resistor type spark plugs. Remove

t h e s p a r k p l u g s a n d e x a m i n e t h e m f o r bu r n e d e l e c -

trodes and fouled, cracked or broken porcelain insu-

l a t or s . K e ep p lu g s a r r a n g ed i n t h e or d er i n w h i ch

t h e y w e r e r e m ov ed f r om t h e e n gi n e. A s in g l e p l u g

d i sp la y i n g a n a b n or m a l con d it i on i n di ca t e s t h a t a

problem exists in the corresponding cylinder. Replace

s p a r k p l u g s a t t h e i n t e r v a l s r e c o m m e n d e d i n Gr o u p

O , L u br i ca t i on a n d M a i n t e n a n ce

Sp a r k p l u g s t h a t h a v e l o w m i l a g e m a y be c l e a n e d

a n d r e us ed i f n ot ot h e r w i s e d e f ect i v e, ca r bo n or oi l

f o u l e d . R e f e r t o t h e Sp a r k P l u g C o n d i t i o n s e c t i o n o f

this group.

SPARK PLUG CABLESSpar k plug cables a re sometimes referred t o as sec-

ondary ignition wires. These cables tra nsfer electrical

current from t he ign ition coil(s) an d/or dist ributor, to

individual spark plugs at each cylinder. The resistive

s p a r k p lu g ca bl e s a r e of n on m e t a l l ic con s t r u ct i on .

Fig. 1 Powertrain Control Module (PCM) Location

(3 ) 3 2- WAYCONNEC-TORSPCM

Fig. 2 Distributor and Camshaft Position Sensor-Typical

SYNC SIGNALGENERATOR CAMSHAFTPOSITION SEN-SORPULSE RINGDISTRIBUTORASSEMBLY

8D - 2 IGNITION SYSTEM XJ

DESCRIPTION AND OPERATION (Continued)


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The cables provide suppression of radio frequency

emissions from the ignition system.

IGNITION COILBattery voltage is supplied to the ignition coil pos-

itive terminal from the ASD relay.

T h e P o w e r t r a i n C o n t r o l M o d u l e (P C M ) o p e n s a n dcloses the ignition coil ground circuit for ignition coil

operation.

Base ignition timing is not adjustable on anyengine. B y con t r o ll in g t h e coi l g r ou n d ci r cu i t , t h eP C M i s a b l e t o s et t h e b a s e t i mi ng a n d a d ju st t h e

ignition t iming advance. This is done to meet chang-

ing engine operating conditions.

The ignition coil is not oi l fi l led. The windings are

embedded in an epoxy compound. This provides heat

a n d v i br a t i o n r e s i s t a n c e t h a t a l l o w s t h e i g n i t i o n c o i l

to be mounted on the engine.

AUTOMATIC SHUTDOWN (ASD) RELAYA s o n e o f i t s f u n c t i o n s , t h e A SD r e l a y w i l l s u p p l y

ba t t e r y v ol t a g e t o t h e i g n it i on coi l . Th e g r ou n d ci r -

cuit for the ASD relay is controlled by the Powertrain

C on t r ol M od u le (P C M ). Th e P C M r eg u la t e s AS D

r el a y oper a t ion b y s w it ch in g t h e g rou n d ci rcu it

on-and-off.

CRANKSHAFT POSITION SENSORTh e cr a n k s h a f t p os i t ion s en s or i s m ou n t e d t o t h e

t r a n s m is si on b el lh ou s in g a t t h e l ef t /r ea r s id e of

engine block (Fig. 3).

Engine speed and crankshaft position are provided

through the cra nkshaft position sensor. The sensor

g e n e r a t e s p u l s e s t h a t a r e t h e i n p u t s e n t t o t h e p o w -

e r t r a i n con t r o l m od u l e (P C M ). Th e P C M i n t e r pr e t s

t h e s en s or i n pu t t o d e t e r m in e t h e cr a n k s h a f t p os i -

t i on . Th e P C M t h en u s es t h i s p os it i on , a l on g w i t h

other inputs, t o determine injector sequence and igni-

tion t iming.

The sensor is a ha ll effect device combined wit h ani n t e r n a l m a g n e t . I t i s a l s o s e n s i t i v e t o s t e e l w i t h i n a

certain distance from it .

SENSOR OPERATION

The flywh eel/drive pla te ha s groups of four notches

a t i t s ou t e r e d ge . O n 4.0L 6-cy l in d e r e n g in e s t h e r e

are three sets of notches (Fig. 5). On 2.5L 4-cylinder

engines there are two sets of notches (Fig. 4).

Th e n ot c h es ca u s e a p u ls e t o be g en e r a t e d w h e n

they pass under the sensor. The pulses are the input

to the PCM. For each engine revolution there are two

groups of four pulses genera ted on 2.5L 4-cylinder

engines. There are 3 groups of four pulses generatedon 4.0L 6-cylinder engines.

The trai l ing edge of the fourth notch, which causes

t h e p ul se, i s f ou r d eg r ee s b ef or e t op d ea d ce nt e r

(TDC) of the corresponding piston.

Th e e n g i n e w i l l n o t op er a t e i f t h e P C M d oe s n o t

receive a crankshaft position sensor input.

CAMSHAFT POSITION SENSORThe camshaft position sensor is located in the dis-

tributor on al l engines.

Th e s en s or con t a i n s a h a l l e ff ect d e vi ce ca l l ed a

s y n c s i g n a l g e n e r a t o r t o g e n e r a t e a f u e l s y n c s i g n a l .

Th i s s y n c s i g n a l g en e r a t o r d e t e ct s a r ot a t i n g p u ls e

ring (shutter) on the distributor shaft . The pulse ring

Fig. 3 Crankshaft Position SensorTypical

ELECTRICALCONNECTOR CLAMP NUT TRANSMISSION BELL-HOUSINGMOUNTING BOLTS (2)CRANKSHAFT POSITION SEN-SORRUBBER GROMMETPIGTAIL HAR-NESS

Fig. 4 Sensor Operation2.5L 4-Cyl. Engine

CRANKSHAFT POSI-TION SENSORNOTCHES FLYWHEEL




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r o t a t e s 1 8 0 d e g r e e s t h r o u g h t h e s y n c s i g n a l g e n e r a -

t o r . I t s s i g n a l i s u s e d i n c o n ju n c t i o n w i t h t h e c r a n k -

s h a f t p os i t ion s en s or t o d i ff er e n t ia t e bet w e e n f u el

injection and spark events. It is also used to synchro-

nize t he fuel injectors with their respective cylinders.

W h e n t h e l e a d i n g e d g e o f t h e p u l s e r i n g (s h u t t e r )

enters t he syn c signal generat or, t he following occurs:

The interruption of magnetic field causes the voltage

t o s w i t c h h i g h r e s u l t i n g i n a s y n c s i g n a l o f a p p r o x i -

mately 5 volts.W h e n t h e t r a i l i n g e d g e o f t h e p u l s e r i n g (s h u t t e r )

leaves the sync signal genera tor, t he following occurs:

The change of the magnetic field causes the sync sig-

n a l v o l t a g e t o s w i t c h l o w t o 0 v o l t s .

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSORF or a n oper a t ion a l d es cr ipt i on , d ia g n os is a n d

removal/instal la tion procedures, refer to G roup 14,

Fu e l S y s t e m.

ENGINE COOLANT TEMPERATURE SENSORF or a n oper a t ion a l d es cr ipt i on , d ia g n os is a n d


Fu e l S y s t e m.

THROTTLE POSITION SENSORF or a n oper a t ion a l d es cr ipt i on , d ia g n os is a n d


Fu e l S y s t e m.

INTAKE MANIFOLD AIR TEMPERATURE SENSORF or a n oper a t ion a l d es cr ipt i on , d ia g n os is a n d

removal/insta l lation procedures, refer to G roup 14,

Fu e l Sy s t e m .

IGNITION SWITCH AND KEY LOCK CYLINDER

The ignition switch is located on the steering col-u m n . Th e Ke y -I n -Sw i t ch i s l oca t e d i n t h e i g n it i on

switch module. For electrical diagnosis of t he K ey-In-

Sw i t ch , r e fe r t o G r ou p 8U , C h i m e/B u z z e r Wa r n i n g

Sy s t e m s . Fo r r e mov a l /i n s t a l l a t i on of e it h e r t h e k ey

l ock cy li n de r or i gn i t ion s w i t ch , r ef er t o I g n it i on

Sw itch and Key Cylinder Removal/Insta l lation in t his

group.

O n v eh i cl es e q u ip pe d w i t h a n a u t o m a t i c t r a n s m is -

sion, a cable connects an interlock device within the

s t e er i n g col u m n a s s e m bl y t o t h e t r a n s m i s s ion f loor

shift lever. This interlock device is used t o lock the

t r a n s m i s s i o n s h i f t e r i n t h e P A R K p o s i t i o n w h e n t h e

key is in the LOCKED or ACCESSORY position. Theinterlock device is not serviceable. If repair is neces-

sary, the steering column assembly must be replaced.

R ef er t o G r o up 19, S t e er in g f or p roce du r es . Th e

s h i ft e r i n t e rl ock ca bl e ca n be a d ju st e d or r e pl a ce d .

Refer t o G roup 21, Tra nsmissions for procedures.

DIAGNOSIS AND TESTING

AUTOMATIC SHUTDOWN (ASD) RELAY TESTTo perform a complete t est of t his relay an d i ts cir-

cu i t r y, r e fe r t o t h e D R B s ca n t o ol . Al s o r ef er t o t h e

appropriate Powertrain Diagnostics Procedures man-u a l . To t e s t t h e r e la y on l y, r e fe r t o R e la y s O pe r a -

tion/Testing in the G roup 14, F uel S ystems section.

TESTING FOR SPARK AT COIL

CAUTION: When disconnecting a high voltagecable from a spark plug or from the distributor cap,

twist the rubber boot slightly (1/2 turn) to break itloose (Fig. 6). Grasp the boot (not the cable) andpull it off with a steady, even force.

(1) Di s con n e ct t h e i g n it i on coi l s econ d a r y ca bl e

f r om ce nt e r t ow e r of t h e d is t r ib u t or ca p . H ol d t h ecable t ermina l a pproximat ely 12 mm (1/2 in.) from a

good engine ground (Fig. 7).

WARNING: BE VERY CAREFUL WHEN THE

ENGINE IS CRANKING. DO NOT PUT YOUR HANDSNEAR THE PULLEYS, BELTS OR THE FAN. DO NOTWEAR LOOSE FITTING CLOTHING.

Fig. 5 Sensor Operation4.0L 6-Cyl. Engine

CRANKSHAFT POSITIONSENSORNOTCHES FLYWHEEL




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(2) Rot a t e (cr a n k) t h e en gi ne w i t h t h e s t a r t er

m ot or a n d ob ser v e t h e ca b l e t e r m in a l f or a s t ea d y

arc. If steady arcing does not occur, inspect the sec-

o n d a r y c o i l c a bl e . R e f e r t o Sp a r k P l u g C a bl e s i n t h i s

group. Also inspect the distributor cap an d rotor for

cr a c k s o r bu r n m a r k s . R e p a i r a s n e ce ss a r y. I f s t e a d y

ar cing occurs, connect ignition coil cable to the dis-

tributor cap.

(3) Remove a cable from one spark plug.

(4) Using insulated pliers, hold the cable terminal

a pproximat ely 12 mm (1/2 in.) from the engine cylin-

d e r h e a d o r bl o c k w h i l e r o t a t i n g t h e e n g i n e w i t h t h e

starter motor. Observe the spark plug cable terminal

for an arc. If steady arcing occurs, i t can be expected

t h a t t h e i g n it i on s econ d a r y s y s t em i s o p er a t i n g cor -

rectly. (If the ignition coil cable is removed forthis test, instead of a spark plug cable, thespark intensity will be much higher). I f s t e a d yarcing occurs at the spark plug cables, but the engine

w i l l n ot s t a r t , con n ect t h e D R B s ca n t ool . R e fe r t o

t h e a p pr op ri a t e P o w er t r a i n D i a g n os t ic P r o ce du r es

service manual .

IGNITION COIL TESTTo perform a complete test of the ignition coil a nd

its circuitry, refer to the DRB scan tool . Also refer to

t h e a p p r op r ia t e P o w e r t r a i n Di a g n o st i cs P r o ce d ur e s

ma nual . To test the coil only, refer to t he following:

The ignition coil (Fig. 8) or (Fig. 9) is designed to

op er a t e w i t h o ut a n e xt e r n a l ba l l a s t r e si s t or .

I n s p ect t h e i g n it i on coi l f or a r c in g . Te st t h e coi l

according to coil t ester ma nufacturers instructions.

Te st t h e coi l p ri m a r y a n d s econ d a r y r es is t a n ce.R e pl a ce a n y coi l t h a t d oe s n ot m e et s pe ci fi ca t i on s .

Refer to the Ignition Coil Resistance chart .

If the ignition coil is being replaced, the secondary

spark plug cable must also be checked. Replace cable

i f i t h a s be e n bu r n e d o r d a m a g e d .

Ar ci n g a t t h e t o w er w i l l c a r bon i z e t h e ca bl e bo ot ,

w h i ch i f i t i s c on n e ct e d t o a n e w i g n it i on coi l, w i l l

cause the coil to fai l .

If the secondary coil cable shows any signs of dam-

a g e , i t s h o u l d be r e p l a c e d w i t h a n e w c a bl e a n d n e w

Fig. 6 Cable Removal

SPARK PLUGCABLE ANDBOOT SPARK PLUG BOOTPULLERTWIST AND PULLSPARK PLUG

Fig. 7 Checking for SparkTypical

A GOODENGINEGROUNDCHECK HEREFOR SPARK IGNITION COIL

Fig. 8 Ignition Coil2.5L Engine

IGNITION COILELECTRICAL CON-NECTORMOUNTING BOLTSSECONDARY CABLE


ELECTRICAL CON-NECTORIGNITION COILMOUNTING BOLTS (2) SECONDARYCABLE


DIAGNOSIS AND TESTING (Continued)


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t e r m in a l . C a r bo n t r a ck in g on t h e o l d c a ble c a n ca u s e

a r c i n g a n d t h e f a i l u r e o f a n e w i g n i t i o n c o i l .

FAILURE TO START TESTTo prevent unnecessary diagnostic t ime a nd wrong

t es t r es ul t s, t h e Tes t in g F or S p a rk At C oi l t es t

should be performed prior to this test .

WARNING: SET PARKING BRAKE OR BLOCK THEDRIVE WHEELS BEFORE PROCEEDING WITH THISTEST.

(1) U n p l u g t h e i g n it i on coi l h a r n e s s con n e ct o r a t

the coil (Fig. 9).

(2) Connect a set of small jumper wires (18 gauge

or smaller) between the disconnected harness termi-

n a l s a n d t h e i g n it i on coi l t e r m in a l s . To d e t er m i n e

p ol a r i t y a t con n e ct o r a n d coi l, r e fe r t o t h e Wi r in g

Diagrams section.

(3) At t a ch on e l ea d of a v ol t m et e r t o t h e p o si t i ve(12 v ol t ) ju m pe r w i r e . At t a ch t h e n e ga t i v e s i d e o f

voltmeter to a good ground.

(4) Determine that sufficient battery voltage (12.4

v ol t s) i s p re se nt f or t h e s t a r t i n g a n d i gn i t ion s y s-

tems.

(5) Crank the engine for 5 seconds while monitor-

i n g t h e v o lt a g e a t t h e coi l p os i t iv e t e r m i n a l :

I f t h e v ol t a ge r em a in s n ea r z er o d ur in g t h e

entire period of cranking, refer to On-Board Diagnos-

t i cs i n G r o up 14, F u el S y s t em s . C h eck t h e P o w er -

t r a in C on t r ol M od ul e (P C M ) a n d a u t o s hu t dow n

relay.

I f v o lt a g e i s a t or n e a r ba t t e r y v o lt a g e a n d d r o psto zero after 1-2 seconds of cranking, check the pow-

e r t r a i n con t r o l m od u l e ci r cu i t . R e fe r t o O n -B o a r d

Diagnostics in Group 14, Fuel Systems.

I f v ol ta g e r em a in s a t or n ea r b a t t er y v ol ta g e

during the entire 5 seconds, turn the key off. Remove

the three 32-way connectors (Fig. 10) from the PCM.

Check 32-way connectors for any spread terminals or

corrosion.

(6) Remove t est lead from the coil positive t ermi-

n a l . C o n n ect a n 18 g a u g e ju m pe r w i r e bet w e e n t h e

battery positive terminal and the coil positive termi-

n a l .(7) M a k e t h e s pe ci a l ju m pe r s h ow n i n (Fi g . 11).

Using the jumper, momentarily ground the ignitioncoil driver circuit at the PCM connector (cavity A-7).

For cavity/terminal locat ion of th is circuit , refer to

Gr o u p 8W, Wi r in g . A s pa r k s h ou l d be g en e r a t e d a t

the coil cable when the ground is removed.

(8 ) I f s p a r k i s g e n e r a t e d , r e p l a c e t h e P C M .

(9 ) I f s p a r k i s n o t s e e n , u s e t h e s p e c i a l ju m p e r t o

ground the coil negative terminal directly.

(10) If spa rk is produced, repair wiring ha rness for

an open condition.

IGNITION COIL RESISTANCE

Fig. 10 PCM and Three 32Way Connectors

Fig. 11 Special Jumper Ground-to-Coil NegativeTerminal




7/22

(11) If spark is n ot produced, replace the ignition

coil.

DISTRIBUTOR CAPR e m o v e t h e d i s t r i bu t o r c a p a n d w i p e i t c l e a n w i t h

a d r y l in t f r ee cl ot h . Vi su a l ly i n sp ect t h e ca p f or

cr a ck s, ca r b on p a t h s , b r ok en t ow e r s or d a m a g e dr ot o r bu t t on (Fi g . 12) or (Fi g . 13). Al s o ch e ck f or

white deposits on the inside (caused by condensation

e n t er i n g t h e ca p t h r o ug h cr a c ks ). R e pl a c e a n y ca p

t h a t d is pl a ys ch a r r ed or er od ed t er m in a l s. Th e

m a ch i ne d s u rf a ce of a t e rm i na l en d (f a ce s t ow a r d

r ot o r ) w i ll i n d ica t e s om e e vi d en ce of e r os i on f r om

normal operation. Examine the terminal ends for evi-

dence of mechanical interference with the rotor t ip.

DISTRIBUTOR ROTORVisually inspect the rotor (Fig. 14) for cra cks, evi-

d en ce of cor r os ion or t h e e ff ect s of a r ci n g on t h e

m et a l t i p. Al so ch eck f or e vi de nce of m ech a n i ca l

i n t e r f e r e n c e w i t h t h e c a p . So m e c h a r r i n g i s n o r m a l

on the end of the metal t ip. The si l icone-dielectric-

v a r n i s h -com p ou n d a p p li ed t o t h e r ot o r t i p f or r a d i o

interference noise suppression, w il l a ppear cha rred.

This is normal. Do not remove the charred com-pound. Te st t h e s pr i ng f or i n su ff ici en t t e n si on .R ep la c e a r ot or t h a t d is pl a y s a n y of t h e se a d v er s e

conditions.

IGNITION TIMING

NOTE: Base (initial) ignition timing is NOT adjust-able on any 2.5L 4-cylinder or 4.0L 6-cylinder

engine. Do not attempt to adjust ignition timing byrotating the distributor.

NOTE: Do not attempt to modify the distributorhousing to get distributor rotation. Distributor posi-tion will have no effect on ignition timing.

All ignition t iming functions are controlled by the

p ow e r t r a in con t r ol m od u le (P C M ). F or a d d i t ion a l

i n for m a t i on , r ef er t o t h e a p pr op ri a t e P o w er t r a i n

Diagnostics Procedures service manual for operation

of t he D RB Scan Tool.

MAP SENSORFor an operational description, diagnosis or remov-

a l / i n s t a l l a t i on p r oce d ur e s, r e fe r t o Gr o u p 14, Fu e l

Systems.

CRANKSHAFT POSITION SENSORTo p e r for m a com p le t e t e st of t h i s s en s or a n d i t s

circuitry, refer to t he D RB scan tool . Also refer t o the

appropriate Powertrain Diagnostics Procedures man-

u a l .

Fig. 12 Cap InspectionExternalTypical

Fig. 13 Cap InspectionInternalTypical

Fig. 14 Rotor InspectionTypical




8/22


tributor (Fig. 15) on al l engines.

To p e r for m a com p le t e t e st of t h i s s en s or a n d i t s

ci r cu i t r y, r e fe r t o t h e a p p r op r ia t e P o w e r t r a i n Di a g -

nostics P rocedures service man ua l. To test th e sensor

only, refer to the following:

For this test, an analog (non-digital) voltme-ter is needed. Do not remove the distributor connec-t or f r om t h e d is t r ib u t or. U s i n g s m a l l p a pe r cl ip s,

i n s e r t t h e m i n t o t h e ba c k s i d e o f t h e d i s t r i bu t o r w i r e

h a r n e s s c on n e ct o r t o m a k e con t a c t w i t h t h e t e r m i-

n a l s. B e s ur e t h a t t h e con n ect or i s n ot d a m a g ed

w h e n i n se rt i n g t h e p a pe r cl ip s. At t a c h v ol t m et e rleads to these paper cl ips.

(1) Connect the positive (+ ) voltmeter lead into t he

s en s or ou t p u t w i r e . Th i s i s a t d on e t h e d i st r i bu t or

wire harness connector. For wire identification, refer

to G roup 8W, Wiring Dia grams.

(2) Connect the negative (-) voltmeter lead into th e

g r ou n d w i r e . Fo r w i r e i d en t i f ica t i o n , r e f er t o Gr o u p

8W, Wiring Dia gra ms.

(3) Set the voltmeter to the 15 Volt DC scale.

(4) R e m ov e d i s t r ibu t or ca p f r om d i s t r ibu t or (t w o

screws). Rotate (crank) the engine unti l the distribu-

tor rotor is approximately in the 11 oclock position.

Th e m ov a b le p ul se r i ng s h ou ld n ow b e w i t h in t h esensor pickup.

(5) Turn ignition key to ON position. Voltmeter

should read approximately 5.0 volts.

(6) I f v ol t a g e i s n ot p r es en t , ch e ck t h e v ol t m et e r

leads for a good connection.

(7) If voltage is st i l l not present, check for voltage

a t t h e s u pp ly w i r e . Fo r w i r e i d en t i f ica t i on , r e fe r t o

G roup 8W, Wiring Dia gra ms.

(8) I f 5 v o lt s i s n o t p r es en t a t s u pp ly w i r e , c h eck

for volta ge at P CM 32-wa y connector (cavity A-17).

Refer t o G roup 8W, Wiring for location of connector/

t e r m in a l . L e a v e t h e P C M con n e ct o r con n e ct e d f or

t h i s t e s t .

(9) I f volta ge is st i l l not present, perform vehicle

t e s t u s i n g t h e DR B s c a n t o o l .

(10) If voltage is present at cavity A-17, but not at

the supply wire:

(a ) C h e c k con t i n u i t y bet w e e n t h e s u pp ly w i r e .This is checked between the distributor connector

a n d ca v i t y A-17 a t t h e P C M . I f con t i nu it y i s n ot

present, repair the harness as necessary.

(b) C h e ck f or con t i n u i t y bet w e e n t h e ca m s h a f t

position sensor output wire and cavity A-18 at the

P C M . I f c o n t i n u i t y i s n o t p r e s e n t , r e p a i r t h e h a r -

ness as necessary.

(c) Check for continuity between the ground cir-

c u i t w i r e a t t h e d i s t r i bu t o r c o n n e c t o r a n d g r o u n d .

I f c o n t i n u i t y i s n o t p r e s e n t , r e p a i r t h e h a r n e s s a s

necessary.

(11) Wh i le ob ser v in g t h e v ol t m et e r, cr a n k t h e

e n gi n e w i t h i g n it i on s w i t ch . Th e v ol t m et e r n e ed l es h ou ld f lu ct u a t e b et w e en 0 a n d 5 v ol t s w h i le t h e

e n gi n e i s cr a n k i n g . Th i s v e r i fi es t h a t t h e ca m s h a f t

position sensor in the distributor is operating prop-

e r l y a n d a s y n c p u l s e s i g n a l i s be i n g g e n e r a t e d .

If sync pulse signal is not present, replacement of

the camshaft position sensor is necessary



Fu e l Sy s t e m .



Fu e l Sy s t e m .

SPARK PLUG CABLESC h e ck t h e s pa r k p lu g ca bl e con n e ct i on s f or g ood

con t a c t a t t h e coi l(s ), d i st r i bu t or ca p t ow e r s, a n d

s p a r k p lu g s . Te r m in a l s s h ou l d be f u ll y s ea t e d . Th e

insulators should be in good condition and should fi t

t ightly on the coil , distributor and spark plugs. Spark

p l u g c a bl e s w i t h i n s u l a t o r s t h a t a r e c r a c k e d o r t o r n

must be replaced.

C l ea n h i gh v ol t a g e i gn i t ion ca b l es w i t h a cl ot h

m oi s t en e d w i t h a n on -f l a m m a bl e s ol ve n t . Wi pe t h e

cables dry. Check for bri t t le or cracked insulation.

TESTING

When testing secondary cables for damage with an

oscilloscope, follow t he in stru ctions of th e equipment

manufacturer.

If an oscilloscope is not available, spark plug cables

m a y be t e s t e d a s f o l l o w s :

Fig. 15 Camshaft Position SensorTypical





9/22

CAUTION: Do not leave any one spark plug cabledisconnected for longer than necessary during test-ing. This may cause possible heat damage to thecatalytic converter. Total test time must not exceedten minutes.

With the engine running, remove spark plug cable

f r om s pa r k p lu g ( on e a t a t i m e) a n d h ol d n e xt t o a

g o o d e n g i n e g r o u n d . I f t h e c a bl e a n d s p a r k p l u g a r e

i n g ood con d i t i on , t h e e n gi n e r p m s h ou l d d r op a n d

t h e e n gi n e w i l l r u n p oor l y. I f e n gi n e r p m d oe s n o t

drop, t he cable a nd/or spark plug ma y not be opera t-

i n g p rop er ly a n d s h ou ld b e r ep la c ed . Al so ch eck

engine cylinder compression.

With the engine not running, connect one end of a

test probe to a good ground. Start the engine and run

t h e ot h er en d of t h e t es t pr ob e a l on g t h e en t ir e

length of al l spark plug cables. If cables are cracked

or p u n ct u r e d , t h e r e w i l l be a n ot i ce a bl e s p a r k ju m p

f r om t h e d a m a g e d a r e a t o t h e t e s t p r obe. Th e c a bl er u n n i n g f r o m t h e i g n i t i o n c o i l t o t h e d i s t r i bu t o r c a p

c a n be c h e c k e d i n t h e s a m e m a n n e r . C r a c k e d , d a m -

a g e d o r f a u l t y c a bl e s s h o u l d be r e p l a c e d w i t h r e s i s -

tance type cable. This can be identified by the words

E L E C T R O N I C S U P P R E S S I O N p r i n t e d o n t h e c a b l e

jacket.

U s e a n oh m m et e r t o t e s t f or op en ci r cu i t s , e x ce s-

s i ve r e si s t a n ce or l oos e t e r m in a l s . R e m ov e t h e d i s-

t r i bu t or ca p f r om t h e d i st r i bu t or. Do not removecables from cap. R e mov e ca bl e f r om s p a r k p lu g .C on n ect oh m m et e r t o s pa r k p lu g t e rm in a l e nd of

ca bl e a n d t o cor r e sp on d i n g e le ct r o de i n d i st r i bu t or

cap. Resistance should be 250 to 1000 Ohms per inchof ca bl e . I f n ot , r e m ov e c a bl e f r o m d i s t r ibu t or ca p

t o w e r a n d con n e ct oh m m et e r t o t h e t e r mi n a l e n d s o f

ca b l e. I f r es is t a n ce i s n ot w i t h in s pe ci fi ca t i on s a s

f ou n d i n t h e S pa r k P l u g C a b le R es is t a n ce ch a r t ,

r e pl a ce t h e ca bl e . Te st a l l s pa r k p lu g ca bl es i n t h i s

m a n n e r .

To t est ignition coil-to-distr ibutor cap cable, d o not

remove the cable from the cap. Connect ohmmeter to

r ot o r bu t t on (ce n t er con t a ct ) of d i s t r ibu t or ca p a n d

terminal at ignition coil end of cable. If resistance is

n o t w i t h i n s p e c i f i c a t i o n s a s f o u n d i n t h e Sp a r k P l u g

C a bl e R es i st a n c e c h a r t , r e m ov e t h e ca bl e f r o m t h e

d i s t r ibu t or ca p . C o n n ect t h e oh m m et e r t o t h e t e r m i-

nal ends of the cable. If resistance is not within spec-

ifica t ion s a s foun d in t he S pa rk P lug C a ble

Resistance chart , replace the cable. Inspect the igni-

tion coil tower for cracks, burns or corrosion.

SPARK PLUG CONDITIONS

NORMAL OPERATING

Th e f ew d e pos i t s p r es en t on t h e s pa r k p lu g w i l l

probably be l ight tan or sl ightly gray in color. This is

e vi de nt w i t h m os t g r a d es of com m er ci a l g a s ol in e

(Fi g . 16). Th e r e w i l l n ot be e vi d en ce of e le ct r o deb ur n in g. G a p g row t h w i ll n ot a v er a g e m or e t h a n

approximately 0.025 mm (.001 in) per 1600 km (1000

m i le s) of op er a t i on . S p a r k p lu g s t h a t h a v e n or m a l

w e a r ca n u s ua l l y b e cl ea n e d , h a v e t h e e le ct r od es

f i l e d , h a v e t h e g a p s e t a n d t h e n be i n s t a l l e d .

So m e f u e l r e f i n e r s i n s e v e r a l a r e a s o f t h e U n i t e d

States have introduced a manganese additive (MMT)

for un leaded fuel . During combustion, fuel w ith MMTc a u s e s t h e e n t i r e t i p o f t h e s p a r k p l u g t o be c o a t e d

w i t h a r u s t col or e d d e p os i t . Th i s r u s t col or ca n be

misdiagnosed as being caused by coolant in the com-

b u st i on ch a m b er. S p a r k p lu g p er f or m a n ce i s n ot

affected by MMT deposits.

COLD FOULING/CARBON FOULING

C o ld f ou l in g i s s om e t im e s r e f er r e d t o a s ca r bo n

fouling. The deposits t ha t cause cold fouling ar e ba si-

cally carbon (Fig. 16). A dry, black deposit on one or

t w o p l u g s i n a s e t m a y be c a u s e d by s t i c k i n g v a l v e s

or defective spark plug cables. Cold (carbon) fouling

o f t h e e n t i r e s e t o f s p a r k p l u g s m a y be c a u s e d by aclogged air cleaner element or repeated short operat-

ing t imes (short trips).

WET FOULING OR GAS FOULING

A spark plug coated with excessive wet fuel or oi l

i s w e t f ou l ed . I n ol d er e n gi n es , w o r n p is t on r i n g s,

leaking valve guide seals or excessive cylinder wear

can cause wet fouling. In new or recently overhauled

engines, wet fouling may occur before break-in (nor-

mal oil control) is achieved. This condition can usu-

MINIMUM MAXIMUM

250 Ohms Per Inch 1000 Ohms Per Inch

3000 Ohms Per Foot 12,000 Ohms Per Foot

SPARK PLUG CABLE RESISTANCE

Fig. 16 Normal Operation and Cold (Carbon) Fouling

NORMAL DRY BLACKDEPOSITS COLD (CARBON) FOULING




10/22

a l l y b e r es ol ve d b y cl ea n i n g a n d r ei n st a l l in g t h e

fouled plugs.

OIL OR ASH ENCRUSTED

I f on e or m or e s pa r k plu gs a r e oil or oil a s h

encrusted (Fig. 17), evaluat e engine condition for the

ca u s e of oi l en t r y i n t o t h a t p a r t icu la r com b us t ion

chamber.

ELECTRODE GAP BRIDGINGE l ect r od e g a p b ri dg in g m a y b e t r a ced t o l oos e

deposits in the combustion cha mber. These deposits

a c cu m u la t e on t h e s pa r k p lu g s d u r in g con t i n uou s

s t op -a n d -g o d r i vi n g . Wh e n t h e e n gi n e i s s u d d en l y

subjected to a high torque load, deposits partial ly l iq-

uefy and bridge the gap between electrodes (Fig. 18).

This short circuits the electrodes. Spa rk plugs wit h

electrode gap bridging can be cleaned using standard

procedures.

SCAVENGER DEPOSITS

Fuel scavenger deposits ma y be either w hite or yel-

l ow (Fi g . 1 9). Th e y m a y a p p ea r t o be h a r m f u l , bu tt h i s i s a n or m a l con d i t i on ca u s e d by ch e m ica l a d d i -

tives in certain fuels. These additives are designed to

change the chemical nature of deposits and decrease

spark plug misfire tendencies. Notice that accumula-

t i on on t h e g r o u n d e l ect r o de a n d s h el l a r e a m a y be

h ea v y, b u t t h e d ep os it s a r e e a s il y r em ov ed . S p a r k

plugs with scavenger deposits can be considered nor-

m a l i n c o n d i t i o n a n d c a n be c l e a n e d u s i n g s t a n d a r d

procedures.

CHIPPED ELECTRODE INSULATOR

A chipped electrode insulator usually results from

b en d in g t h e ce nt e r el ect r od e w h i le a d ju s t in g t h e

s p a r k p lu g e le ct r o de g a p . U n d e r ce r t a i n con d i t i on s ,

s ev er e d et on a t i on ca n a l s o s ep a r a t e t h e i n su la t o r

from the center electrode (Fig. 20). Spark plugs with

this condition must be replaced.

PREIGNITION DAMAGE

Preignition damage is usually caused by excessive

combustion chamber tempera ture. The center elec-t r o d e d i s s ol v es f ir s t a n d t h e g r ou n d e le ct r o de d i s-

s ol v es s om e w h a t l a t t e r (Fi g . 21). I n s u l a t or s a p p ea r

r e la t i ve ly d e pos i t f r ee . D e t er m i n e i f t h e s pa r k p lu g

h a s t h e cor r ect h ea t r a n ge r a t i ng f or t h e en gi ne.

De t e r m in e i f i g n it i on t i m i n g i s ov er a d v a n c ed or i f

other opera ting conditions are causing engine over-

h e a t i n g . (T h e h e a t r a n g e r a t i n g r e f e r s t o t h e o p e r a t -

i ng t em per a t u re of a pa r t icu la r t y pe s pa r k pl ug .

Sp a r k p l u g s a r e d e s i g n e d t o o p e r a t e w i t h i n s p e c i f i c

t e m pe r a t u r e r a n g e s . Th i s d ep en d s u p on t h e t h i ck -

Fig. 17 Oil or Ash Encrusted

Fig. 18 Electrode Gap Bridging

GROUNDELECTRODE DEPOSITSCENTERELECTRODE

Fig. 19 Scavenger Deposits

GROUND ELECTRODE COVERED WITH WHITE OR YELLOW DEPOSITSCENTERELEC-TRODE




11/22

n e ss a n d l en g t h of t h e ce n t er e le ct r o de s p or ce la i n

insulator.)

SPARK PLUG OVERHEATING

O v e r h e a t i n g i s i n d i c a t e d by a w h i t e o r g r a y c e n t e r

e le ct r o de i n s ul a t o r t h a t a l s o a p p ea r s bl is t e r ed (Fi g .

22). The increase in electrode gap wil l be consider-

ably in excess of 0.001 inch per 1000 miles of opera-

t i on . Th i s s u g ge st s t h a t a p lu g w i t h a cool er h ea t

r a n g e r a t i n g s h ou l d be u s ed . O v er a d v a n c ed i g n it i on

t i m i n g, d e t on a t i on a n d cool in g s y s t em m a l f u n ct i on s

can also cause spark plug overheating.

REMOVAL AND INSTALLATION

SPARK PLUG CABLES

CAUTION: When disconnecting a high voltagecable from a spark plug or from the distributor cap,twist the rubber boot slightly (1/2 turn) to break itloose (Fig. 23). Grasp the boot (not the cable) and

pull it off with a steady, even force.

Instal l cables into the proper engine cylinder firing

order (Fig. 24) or (Fig. 25).

Fig. 20 Chipped Electrode Insulator

GROUNDELECTRODE CENTERELECTRODECHIPPEDINSULATOR

Fig. 21 Preignition Damage

GROUNDELECTRODESTARTING TODISSOLVE CENTERELECTRODEDISSOLVED

Fig. 22 Spark Plug Overheating

B LI ST ER ED WH IT E ORGRAY COLORED INSULATOR

Fig. 23 Cable Removal

SPARK PLUGCABLE ANDBOOT SPARK PLUG BOOTPULLERTWIST AND PULLSPARK PLUG

Fig. 24 Engine Firing Order2.5L 4-Cylinder Engine

FIRING ORDER:1 3 4 2CLOCKWISE ROTA-TION FRONT




12/22

Wh en r ep la c in g t h e s pa r k p lu g a n d coi l ca b l es ,

r ou t e t h e ca bl es cor r e ct l y a n d s ecu r e i n t h e p r op er

r e t a i n er s . F a i l u r e t o r ou t e t h e ca bl es p r op er l y ca n

cause the radio to reproduce ignition noise. It could

also cause cross ignition of the plugs or short circuit

the cables to ground.

Wh e n i n s t a l l in g n e w ca bl es , m a k e s u r e a p os i t iv e

con n ect i on i s m a d e. A s n a p s h ou ld b e f e lt w h e n a

good connection is made between the plug cable and

the distributor cap tower.

SPARK PLUGS

PLUG REMOVAL

(1) Al w a y s r em ov e s pa r k p lu g or i gn i t ion coi lcables by grasping at the cable boot (Fig. 23). Turn

t h e ca bl e bo ot 1/2 t u r n a n d p u ll s t r a i g h t ba c k i n a

s t ea d y m ot i on . N ev er p ul l d i rect l y on t h e ca b l e.

I n t e r n a l d a m a g e t o c a bl e w i l l r e s u l t .

(2) P r i or t o r e mov i n g t h e s pa r k p lu g , s p ra y com -

p r e s s e d a i r a r o u n d t h e s p a r k p l u g h o l e a n d t h e a r e a

ar ound the spark plug. This w il l help prevent foreign

material from entering the combustion chamber.

(3) R e m ov e t h e s p a r k p lu g u s in g a q u a l i t y s ock et

w i t h a r u bbe r o r f o a m i n s e r t .

(4) I n s pect t h e s pa r k p lu g con d it i on . R ef er t o

Sp a r k P l u g s i n t h e Di a g n o st i cs /Se r v ice P r o ce d ur e s

section of this group.

PLUG CLEANING

Th e p lu g s m a y b e cl ea n e d u s in g com m er ci a l ly

ava ilable spark plug cleaning equipment. After clean -

i n g , f i le t h e c en t e r e le ct r o d e f la t w i t h a s m a l l p o in t

fi le or jewelers fi le before adjusting gap.

CAUTION: Never use a motorized wire wheel brushto clean the spark plugs. Metallic deposits will

remain on the spark plug insulator and will causeplug misfire.

PLUG GAP ADJUSTMENT

C h e ck t h e s pa r k p lu g g a p w i t h a g a p g a u g e t ool . I f

t h e g a p i s n ot cor r ect , a d ju st i t b y b en d in g t h e

ground electrode (Fig. 26). Never attempt to adjustthe gap by bending the center electrode.

SPARK PLUG GAP

2.5L 4-Cylinder Engine Spark Plug Gap: .89 mm

(.035 in).

4.0L 6-Cylinder Engine Spark Plug Gap: .89 mm(.035 in).

PLUG INSTALLATION

Always t ighten spark plugs to the specified torque.

Over t ightening can cause distortion. This ma y result

i n a c h a n g e i n t h e s p a r k p l u g g a p , o r a c r a c k e d p o r -

celain insulator.

Wh e n r e pl a ci n g t h e s pa r k p lu g a n d i g n it i on coi l

cables, route the cables correctly and secure them in

the appropriate retainers. Failure to route the cables

p r op er l y ca n ca u s e t h e r a d i o t o r e pr od u ce i g n it i on

noise. It could cause cross ignition of the spark plugs,

or short circuit the cables to ground.(1 ) St a r t t h e s p a r k p l u g i n t o t h e c y l i n d e r h e a d by

h a n d t o a v o i d c r o s s t h r e a d i n g .

(2) Tighten the spark plugs to 35-41 Nm (26-30 ft.

lbs.) torque.

(3) Instal l spark plug cables over spark plugs.

IGNITION COILThe ignition coil is an epoxy fi l led type. If the coil

i s r e p l a c e d , i t m u s t be r e p l a c e d w i t h t h e s a m e t y p e .

Fig. 25 Engine Firing Order4.0L 6-Cylinder Engine

Fig. 26 Setting Spark Plug GapTypical


REMOVAL AND INSTALLATION (Continued)


13/22

REMOVAL

On the 2.5L 4-cylinder engine, the ignition coil is

m ou n t ed t o a b r a ck et on s id e o f e ng in e (t o r ea r of

distributor) (Fig. 27).

On the 4.0L 6-cylinder engine, the ignition coil is

m ou n t e d t o a br a c ke t on s i de o f e n g i n e (t o f r o n t o f

distributor) (Fig. 28).

(1) Disconnect ignition coil seconda ry cable from

ignition coil.

(2) Disconnect engine harness connector from igni-tion coil.

(3) Remove ignition coil mounting bolts (nuts ar e

used on back side of bracket on some coils).

(4) Remove coil from vehicle.

INSTALLATION

(1) Install ignition coil to bracket on cylinder block

w i th m ou nt in g b olt s (a n d n ut s if eq uipped ). I f

equipped with nuts and bolts, t ighten to 11 Nm (100

in. lbs.) torque. If equipped with bolts only, t ighten t o

5 Nm (50 in. lbs.) torque.

(2) Connect engine harness connector to coil.

(3) Connect ignition coil cable to ignition coil.

AUTOMATIC SHUTDOWN (ASD) RELAYThe ASD relay is located in the power distribution

center (PDC). The PDC is located in engine compart-

ment (Fig. 29). Refer to label on PDC cover for relaylocation .

REMOVAL(1) Remove PDC cover.

(2) Remove relay by l i ft ing straight up.

INSTALLATION

(1) Check condition of relay wire terminals at PDC

for corrosion or damage. Also check heights of relay

t e r m i n a l p i n s a t P DC . P i n h e i g h t s h o u l d be t h e s a m e

f or a l l p in s . R ep a ir a s n eces sa r y b ef or e i n st a l l in g

relay.

(2) Push relay into connector.

(3) Instal l relay cover.

CRANKSHAFT POSITION SENSORTh e cr a n k s h a f t p os i t ion s en s or i s m ou n t e d t o t h e

t r a n s m is si on b el lh ou s in g a t t h e l ef t /r ea r s id e of

engine block (Fig. 30) or (Fig. 31).

On 2.5L 4-cylinder equipped with a manual trans-

m i ss ion , t h e s en s or i s a t t a ch ed w i t h t w o b ol t s. O n

2 .5 L e n g i n e s e q u i p p e d w i t h a n a u t o m a t i c t r a n s m i s -

s i o n , t h e s e n s o r i s a t t a c h e d w i t h t w o n u t s . A l l 4 .0 L

6-cylinder engines have the sensor attached with two

bolts.


IGNITION COILELECTRICAL CON-NECTORMOUNTING BOLTSSECONDARY CABLE


ELECTRICAL CON-NECTORIGNITION COILMOUNTING BOLTS (2) SECONDARYCABLE

Fig. 29 PDC Location

POWER DISTRIBUTION CEN-TER (PDC)




14/22

REMOVAL

S om e m od el /e ng in e com b in a t i on s m a y r eq u ir e

removal of air cleaner tubes for access to sensor.

(1) Remove a ir cleaner tube(s) at throttle body (i f

necessary).

(2) Near rear of intake manifold, disconnect pigtai l

ha rness (electrical connector) from main electrical

harness.

(3) Remove nut holding sensor harness wire clamp

t o f u e l r a i l m o u n t i n g s t u d .

(4) Depending upon application, remove either sen-

sor mounting bolts or nuts.

(5) Remove sens or.

(6) Remove clamp from sensor wire harness.

INSTALLATION

(1) I n s t a l l s e n s or f lu s h a g a i n s t op en i n g i n t r a n s -

mission housing.

(2) 2 .5L e n g in e s e q u ip pe d w i t h a u t o m a t i c t r a n s -

m i ss ion : I n s t a l l a n d t i g ht e n t w o s en s or m ou n t in g

nuts to 19 Nm (14 ft . lbs.) torque.

(3) 2.5L e n gi n es e q u ip pe d w i t h m a n u a l t r a n s m i s -

sion or any 4.0L engines: Instal l and t ighten two sen-

sor mounting bolts to 19 Nm (14 ft. lbs.) torque. Thetwo sensor mounting bolts are speciallymachined to correctly space unit to flywheel.Do not attempt to install any other bolts.

(4) Connect sensor pigtai l ha rness electrical con-n e c t o r t o m a i n w i r i n g h a r n e s s .

(5) Instal l clamp on sensor wire harness.

(6) Instal l clamp over fuel rai l mounting stud.

(7) I n s t a l l cl a m p m o u n t i n g n u t .

(8) Instal l air cleaner tube to throttle body (i f nec-

essary).


tributor (Fig. 32).

REMOVAL

D i st r i bu t or r em ov a l i s n ot n ece ss a r y t o r em ov ecamshaft position sensor.

(1) Disconnect negative battery cable at battery.

(2) R e m ov e d i st r i bu t or ca p f r om d i s t r ibu t or (t w o

screws).

(3) Di s con n e ct ca m s h a f t p os i t ion s en s or w i r i n g

h a r n e s s f r o m m a i n e n g i n e w i r i n g h a r n e s s .

Fig. 30 Crankshaft Position Sensor2.5L 4-Cyl.Engine With Auto. Trans.

Fig. 31 Crankshaft Position SensorExcept 2.5L4-Cyl. Engine With Auto. Trans.

Fig. 32 Camshaft Position Sensor





15/22

(4) Remove distributor rotor from distributor sha ft .

(5) L i ft ca m s h a f t p os i t ion s en s or a s s e m bl y f r om

distributor housing (Fig. 32).

INSTALLATION

(1) Insta l l camsha ft position sensor to distr ibutor.

Align sensor into notch on distributor housing.

(2) Connect wiring harness.

(3) Instal l rotor.

(4) I n st a l l d is t ri bu t or ca p . Ti gh t en m ou nt i ng

screws.

MANIFOLD ABSOLUTE PRESSURE (MAP) SENSORF or r em ov a l a n d i n st a l l a t i on , r ef er t o M a n if ol d

Absolute Pressure Sensor in group 14, Fuel Systems.



Fu e l S y s t e m.

THROTTLE POSITION SENSORF or a n oper a t ion a l d es cr ipt i on , d ia g n os is a n d


Fu e l S y s t e m.



Fu e l S y s t e m.

DISTRIBUTOR

Al l d is t r ib ut or s con t a i n a n i n t er n a l oi l s ea l t h a tp r ev en t s oi l f r om e n t er i n g t h e d i st r i bu t or h ou s in g .

The seal is not serviceable.

Fa ctory replacement distr ibutors a re equipped w ith

a p l a s t i c a l i g n m e n t p i n a l r e a d y i n s t a l l e d . T h e p i n i s

located in an access hole on the bottom of the distrib-

utor housing (Fig. 33). It is used to temporarily lock

t h e r ot o r t o t h e cy l in d e r n u m be r 1 p os i t ion d u r i n g

i n s t a l l a t i on . Th e p in m u s t be r e m ov ed a f t e r i n s t a l l -

i n g t h e d i s t r ibu t or .

The camshaft position sensor is located in the dis-

tributor on al l engines (Fig. 34). For removal/instal-

lation procedures, refer to Camshaft Position Sensor.

D i s t ri bu t or r em ov a l i s n ot n ece ss a r y f or s en s orremoval.

Refer to (Fig. 34) for an exploded view of the dis-

tributor.

A fork with a slot is supplied on the bottom of the

d i st r i bu t or h ou s in g w h e r e t h e h ou s in g b a s e s ea t s

against the engine block (Fig. 34). The centerl ine of

t h e s lot a l i gn s w i t h t h e d i st r i bu t or h ol dd ow n b ol t

hole in the engine block. Because of the fork, the dis-

tributor cannot be rotated. Distributor rotation is not

n eces sa r y a s a l l i gn i t ion t i m in g r eq u ir em en t s a r e

handled by the powertrain control module (PCM).

The position of the distributor determines fuel syn-

chronization only. It does not determine ignition t im-

ing.

Fig. 33 Plastic Alignment Pin

PLASTIC ALIGN-MENT PIN

Fig. 34 Distributor2.5L Or 4.0L EnginesTypical

CAPCAMSHAFTPOSITIONSENSOR HOUSINGHOL DDO WNBOLTHOLDDOWNCLAMPFORK WITH SLOTGASKETWASHERROLL PINDRIVE GEARSHAFTPULSE RINGROTOR




16/22

NOTE: Do not attempt to modify this fork to attainignition timing.

REMOVAL2.5L OR 4.0L ENGINE

(1) D i s con n ect t h e n eg a t i ve b a t t e ry ca b l e a t t h e

battery.

(2) Disconnect coil secondary cable at coil.

(3) R em ov e d is t r ib ut or ca p f r om d i st r i bu t or (2

s cr ew s ). D o n ot r em ov e ca b l es f r om ca p . D o n ot

remove rotor.

(4) Disconnect the distributor wiring harness from

t h e m a i n e n g i n e h a r n e s s .

(5) Remove the cylinder number 1 spark plug.

(6) H ol d a f i n ge r ov er t h e op en s pa r k p lu g h ol e.

R ot a t e t h e e ng in e a t t h e v ib r a t i on d a m p en er b ol t

until compression (pressure) is felt.

(7) S l ow l y con t i n u e t o r o t a t e t h e e n g in e . D o t h i s

u n t i l t h e t i m i n g i n d ex m a r k o n t h e v i bra t i on d a m p e r

pulley al igns with the top dead center (TDC) mark (0d eg r ee ) on t i m in g d eg r ee s ca l e (F i g. 35). Al w a y s

r o t a t e t h e e n g i n e i n d i r e c t i o n o f n o r m a l r o t a t i o n . Do

n o t r o t a t e t h e e n g i n e b a c k w a r d t o a l i g n t h e t i m i n g

m a r k s .

(8) On models equipped w ith A/C, remove th e elec-

trical cooling fan and shroud assembly from the radi-

a t or. R efer t o G r oup 7, C oolin g S yst em for

procedures.

(9) Th i s w i ll p rov id e r oom t o t u r n t h e e ng in e

cr a n k s h a f t w i t h a s ock et a n d r a t ch e t u s i n g t h e v i bra -

tion damper bolt .

(10) R em ov e t h e d i st r i bu t or h ol dd ow n b ol t a n d

clamp.

(11) Remove the distributor from engine by slowly

l if t i n g s t r a i g h t u p .

(12) N ot e t h a t t h e r ot or w i l l r ot a t e s li gh t l y i n a

cou n t e r cl ock w i s e d i r ect i on w h i l e l if t i n g u p t h e d i s-

tributor. The oil pump gear wil l a lso rota te sl ightly in

a counterclockwise direction while l i ft ing up the dis-

t r i bu t o r . T h i s i s d u e t o t h e h e l i c a l c u t g e a r s o n t h ed i s t r i bu t o r a n d c a m s h a f t .

(13) Note the removed position of the rotor during

d i s t r i bu t o r r e m o v a l . Du r i n g i n s t a l l a t i o n , t h i s w i l l be

referred to as the Pre-position.

(14) 2.5L 4-Cylinder Engine: Observe th e slot inthe oil pump gear through the hole on the side of the

engine. It should be slightly before (counterclockwise

of) the 10 oclock position (Fig. 36).

(15) 4.0L 6-Cylinder Engine: Observe th e slot inthe oil pump gear through the hole on the side of the

engine. It should be slightly before (counterclockwise

of) the 11 oclock position (Fig. 37).

(16) Remove and discard the old distributor-to-en-

gine block gasket.

Fig. 35 Align Timing Marks

CRANKSHAFT VIBRATIONDAMPER TIMING MARK

Fig. 36 Slot At 10 Oclock Position2.5L Engine

Fig. 37 Slot At 11 Oclock Position4.0L Engine

FRONT11 OCLOCK POSITION OIL PUMP SLOT




17/22

INSTALLATION

(1) I f t h e e n g i n e cr a n k s h a f t h a s bee n r o t a t e d a f t e r

d i st r i bu t or r em ov a l , cy l in d er n u m ber 1 m u st b e

returned to i t s proper firing stroke. Refer to previous

R E M O VAL St e p 5 a n d St e p 6. Th e se s t e ps m u s t be

done before insta l l ing distributor.

(2) Check the position of the slot on the oil pumpg ea r . O n t h e 2.5L e n gi n e, i t s h ou l d be ju s t s l ig h t l y

before (count erclockwise of) th e 10 oclock position

(F i g. 36). O n t h e 4. 0L en g in e, i t s h ou l d b e ju s t

sl ightly before (counterclockwise of) the 11 oclock

p os i t ion (Fi g . 3 7). I f n ot , p la c e a f l a t bl a d e s c r ew -

d r i v e r i n t o t h e o i l p u m p g e a r a n d r o t a t e i t i n t o t h e

proper position.

(3) Fa ctory replacement distributors a re equipped

w i t h a p la s t i c a l i g n m en t p in a l r e a d y i n s t a l l e d (Fi g .

33). This pin is used to temporarily hold the rotor to

the cylinder number 1 firing position during distrib-

u t or i n s t a l l a t i on . I f t h i s p i n i s i n p la c e, p r oce ed t o

Step 8. If not, proceed to next step.(4) I f t h e or i g in a l d i s t r ibu t or i s t o be r e i n s t a l l ed ,

s u c h a s d u r i n g e n g i n e o v e r h a u l , t h e p l a s t i c p i n w i l l

not be a vaila ble. A 3/16 inch d rift pin punch t ool ma y

be s u bs t i t u t ed f or t h e p la s t i c p i n .

(5) Remove the camshaft position sensor from the

distributor housing. Lift straight up.

(6) Four different al ignment holes are provided on

the plastic ring (Fig. 38). Note that 2.5L and 4.0Lengines have different alignment holes (Fig.38).

(7 ) R o t a t e t h e d i s t r i bu t o r s h a f t a n d i n s t a l l t h e p i n

punch tool through the proper al ignment hole in the

plastic ring (Fig. 38) and into the mating access holein the distributor housing. This wil l prevent the dis-

t r i bu t o r s h a f t a n d r o t o r f r o m r o t a t i n g .

(8) Clean the distributor mounting hole area of the

engine block.

(9) Install a new distributor-to-engine block gasket

(Fig. 34).

(10) I n s t a l l t h e r ot o r t o t h e d i s t r ibu t or s h a f t .

(11) 2.5L 4-Cylinder Engine: P re-position thed i s t r ibu t or i n t o t h e e n gi n e w h i l e h o ld i n g t h e ce n t er -

line of the base slot in the 1 oclock position (Fig. 39).

C o n t i n u e t o e n g a g e t h e d i s t r i bu t o r i n t o t h e e n g i n e .

The rotor a nd distributor w il l rotat e clockwise during

i n s t a l l a t i on . Th i s i s d u e t o t h e h e li ca l cu t g ea r s on

the distributor and camshaft . When the distributor is

fully seated to the engine block, the centerl ine of the

base slot should be al igned to the clamp bolt mount-

i n g h ol e on t h e e n gi n e (Fi g . 40). Th e r ot o r s h ou l d

a l s o b e p oi n t ed s li gh t l y p a s t (cl ock w i se of ) t h e 3

oclock position.

4.0L 6-Cylinder Engine: P re-position the distrib-u t o r i n t o t h e e n g i n e w h i l e h o l d i n g t h e c e n t e r l i n e o f

the base slot in the 1 oclock position (Fig. 39). Con-

t i n u e t o e n g a g e t h e d i s t r i bu t o r i n t o t h e e n g i n e . T h e

r ot or a n d d is t r ib u t or w i ll r ot a t e cl ock w i se d u r in g

i n s t a l la t i on . Th i s i s d u e t o t h e h e li ca l cu t g ea r s on

the distributor and camshaft . When the distributor is

fully seated to the engine block, the centerl ine of the

base slot should be al igned to the clamp bolt mount-

i n g h ol e on t h e e n gi n e (Fi g . 41). Th e r ot o r s h ou l d

also be pointed at the 5 oclock position.

I t m a y be n e ce ss a r y t o r o t a t e t h e r ot o r a n d d i s t r ib-

u t or s h a f t (v er y s l ig h t l y ) t o e n g a g e t h e d i st r i bu t or

s h a f t w i t h t h e s l ot i n t h e o il p um p g e a r. Th e s a m e

m a y h a v e t o b e d on e t o e n g a g e t h e d is t r ib ut or g ea r

w i t h t h e c a m sh a f t g ea r .

The distributor is correctly installed when: t h e r ot or i s p oi n t ed a t t h e 3 ocl ock p os it i on

(2.5L e n gi n e), or a t t h e 5 ocl ock p os i t ion (4.0L

engine).

t h e p la s t i c a l ig n m en t p in (or p in p u n ch t o ol ) i s

sti l l instal led to distributor.

t h e n u m be r 1 c y l i n d e r p i s t o n i s s e t a t t o p d e a d

center (TDC) (compression stroke).

t h e c e n t e r l i n e o f t h e s l o t a t t h e ba s e o f t h e d i s -

tributor is al igned to the centerl ine of the distributorh ol d d ow n bol t h ol e o n t h e e n gi n e. I n t h i s p os i t ion ,

the holddown bolt should easily pass through the slot

a n d i n t o t h e e n g i n e .

N o a d ju s t men t s a r e n eces sa r y. P r o ce ed t o n ex t

step.

(12) I n s t a l l t h e d is t r ib ut or h ol d dow n cl a m p a n d

bolt . Tighten the bolt to 23 Nm (17 ft . lbs.) torque.

(13) Remove the pin punch tool from the distribu-

tor. Or, i f the plastic al ignment pin was used, remove

i t s t r a i g h t d o w n f r o m t h e bo t t o m o f t h e d i s t r i bu t o r .

Discard plastic pin.

Fig. 38 Pin Alignment Holes

DISTRIBUTORHOUSING (TOPVIEW) PULSE RING 4.0L 6-CYLIN-D ER EN GI NEALIGN. HOLE2.5L 4-CYLIN-D ER E NGI NEALIGN. HOLEMATING ACCESS HOLE INDISTRIBUTOR HOUSINGPLASTIC RING




18/22

(14) If removed, instal l the camshaft position sen-

sor to the distributor. Align the wiring harness grom-

m e t t o t h e n ot c h i n t h e d i s t r ibu t or h ou s in g .

(15) Instal l the rotor.

CAUTION: If the distributor cap is incorrectly posi-tioned on distributor housing, the cap or rotor maybe damaged when engine is started.

(16) Insta l l th e distributor cap. Tighten d istributor

cap holddown screws to 3 Nm (26 in. lbs.) torque.

(17) I f r e mov ed , i n s t a l l t h e s pa r k p lu g ca bl e s t o

the distributor cap. F or proper firing order, refer to

t h e Sp e ci f ica t i o n s s e ct i on a t t h e e n d o f t h i s g r ou p .

See Engine Firing Order.

(18) C o nn e ct t h e d i s t r ibu t or w i r i n g h a r n e ss t o t h e

m a i n e n g in e h a r n e ss .

(19) Connect battery cable to battery.

POWERTRAIN CONTROL MODULE (PCM)Refer to Group 14, Fuel System for procedures.

IGNITION SWITCH AND KEY CYLINDERTh e i g n it i on k ey m u s t be i n t h e k ey cy l in d e r f o r

cylinder removal . The key cylinder must be removed

first before removing ignition switch.

KEY CYLINDER REMOVAL

(1) Disconnect negative battery cable at battery.

(2) I f e q ui pp ed w i t h a n a u t om a t i c t r a n s m is si on ,

place shifter in PARK position.

(3) Rotate key to ON position.

(4) A release tang is located on bottom of key cyl-

inder (Fig. 42).

(5) Position a small screwdriver or pin punch into

tang access hole on bottom of steering column lower

cover (Fig. 43).

(6) Push the pin punch up while pull ing key cylin-

der from steering column.

Fig. 39 Distributor Pre-positionAll Engines

1 OCLOCKPOSITION FRONTBASE SLOTDISTRIBUTOR BASE

Fig. 40 Distributor Engaged Position2.5L4-Cylinder Engine

DISTRIBUTOR BASESL OTC LA MP BO LTMOUNTING HOLE(ON ENGINE)DISTRIBUTORBASE FRONT

Fig. 41 Distributor Engaged Position4.0L6-Cylinder Engine

DISTRIBUTORBASE SLOTCLAMP BOLT MOUNTINGHOLE (ON ENGINE)DISTRIBUTORBASE FRONT




19/22

IGNITION SWITCH REMOVAL

(1) Remove key cylinder. Refer to previous steps.

(2) R e m ov e l ow e r s t e er i n g col u m n cov er s cr e w s

and remove cover (Fig. 43).

(3) Remove ignition switch mounting screw (Fig.46). Use tamper proof torx bit (Snap-On SDMTR10

or equivalent) to remove the screw.

(4) Using a small screwdriver, push on locking tab

(Fig. 44) and remove switch from steering column.

(5) D isconnect tw o electrical connectors at rear of

ignition switch (Fig. 46).

IGNITION SWITCH INSTALLATION

(1) Before instal l ing ignition switch, rotate the slot

in the switch to the ON position (Fig. 45).

(2) C on n e ct t w o e le ct r i ca l con n e ct o r s t o r e a r of

ignition switch. Make sure that locking tabs are fully

seated into wiring connectors.

(3) P os i t ion s w i t ch t o c ol u m n a n d i n s t a l l t a m p e r

proof screw. Tighten screw to 3 Nm (26 in. lbs.).(4) Install steering column lower cover.

KEY CYLINDER INSTALLATION

(1) I f e q ui pp ed w i t h a n a u t om a t i c t r a n s m is si on ,

place shifter in PARK position.

(2) Position key cylinder into steering column as i t

would normally be in the ON position.

(3) P r e ss k ey cy l in d e r i n t o c ol u m n u n t i l i t s n a p s

into position.

(4) Check mechanical operation of sw itch. Auto-matic Transmission: B e s u r e t r a n s m i s s i o n l e v e r i s

Fig. 42 Key Cylinder Release Tang

KEY CYLINDERRELEASE TANG

Fig. 43 Key Cylinder and Cover Removal

LOWERCOVER ACCESSHOLE PIN PUNCHCOVERSCREWS (3)

Fig. 44 Ignition Switch Lock Tab

LOCK TABIGNITION SWITCHSCREWDRIVER

Fig. 45 Switch In ON Position

IGNITION SWITCHROTATE TO ON POSITION




20/22

locked in PARK position after key removal . If key is

d i ff i cu l t t o r ot a t e or i s d i ff i cu l t t o r e mov e, t h e s h i ft

lever-to-steering column cable ma y be out of adjust-

ment or defective. Refer to G roup 21, Tran smission

for procedures. Manual Transmission: B e s u r e k e ycannot be removed unti l release lever is operated. If

key can be removed, release lever mechanism may be

defective. Release lever mecha nism is not serviced

separ at ely. If repair is necessary, the steering columnm u s t be r e p la c ed . R e fe r t o Gr o u p 1 9, St e e r in g f or

procedures.

(5) Connect negative cable to battery.

(6) Check electrical operation of switch.

SHIFTER/IGNITION INTERLOCKO n m o d e l s e q u i p p e d w i t h a n a u t o m a t i c t r a n s m i s -

s ion , a ca b l e c on n ect s t h e i gn i t ion s w i t ch w i t h t h e

f l oor s h i ft l ev er. Th e s h i ft e r w i l l be l ock ed i n t h e

PARK position when the ignition key is in the LOCK

or ACCESSORY positions. The cable can be adjusted

or r e pl a ce d . R e fe r t o Gr o u p 21, Tr a n s m i s si on s f or

procedures. The ignition interlock device w ithin thesteering column is not serviceable. If service is nec-

essary, the steering column must be replaced. Refer

to Group 19, Steering for procedures.

SPECIFICATIONS

VECI LABELIf anything differs between the specifications found

on the Vehicle Emission Control Information (VECI)

label an d the following specificat ions, use specifica-

tions on VECI label . The VECI label is located in the

engine compartm ent.

IGNITION TIMINGI g n it i on t i m in g i s n ot a d ju s t a b le on a n y e ng in e.

Refer to Ignition Timing in the Dia gnostics/Service

P r oce d ur e s s ect i on of t h i s g r ou p f or m or e i n for m a -tion.

ENGINE FIRING ORDER 2. 5L 4 -CYLINDERENGINE

ENGINE FIRING ORDER 4. 0L 6 -CYLINDERENGINE

Fig. 46 Ignition Switch Removal/Installation

TAMPERPROOFSCREWIGNITIONSWITCHELECTRICAL CONNECTORS FIRING ORDER:1 3 4 2CLOCKWISE ROTA-TION FRONT

FIRING ORDER:1 5 3 6 2 4CLOCKWISE ROTATIONFRONT




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SPARK PLUGS SPARK PLUG CABLE RESISTANCE

IGNITION COIL RESISTANCE

TORQUE CHART

DESCRIPTION TORQUE

Crankshaft Position SensorMounting B olts . . . . . . . . . . . . 19 Nm (14 ft . lbs.)

Crankshaft Position Sensor

Mounting Nut s . . . . . . . . . . . . 19 Nm (14 ft . lbs.)

Distributor Hold Down B olt . . . . 23 Nm (17 ft . lbs.)

Ignition C oil Mounting

(if ta pped bolts ar e used) . . . . . 5 Nm (50 in. lbs.)

Ignition C oil Mounting

(if nut s/bolts a re used) . . . . . 11 Nm (100 in. lbs.)

Powertrain Control Module (PCM)

Mounting S crews . . . . . . . . . . . . 1 Nm (9 in. lbs.)

Spa rk P lugs (al l engines) . . . . . . 41 Nm (30 ft . lbs.)

ENGINE PLUG TYPEELECTRODE

GAP

2.5/4.0L RC12LYC 0.89 mm(0.035 in.)

MINIMUM MAXIMUM

250 Ohms Per Inch 1000 Ohms Per Inch

3000 Ohms Per Foot 12,000 Ohms Per Foot

COIL TOYODENSO DIAMOND

Primary Resistance .95 - 1.20 Ohms .96 - 1.18 Ohms

Secondary Resistance at 70- 80F 11,300 - 13,300 Ohms 11,300 - 15,300 Ohms


SPECIFICATIONS (Continued)


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EXJ_8D99 jeep xj service manual

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