JEEP CHEROKEE 1995 Service Repair Manual

REMOVALÐ2.5L OR 4.0L ENGINE
(1) Disconnect the negative battery cable at the
battery.
(2) Disconnect coil secondary cable at coil.
(3) Remove distributor cap from distributor (2
screws). Do not remove cables from cap. Do not re-
move rotor.
(4) Disconnect the distributor wiring harness from
the main engine harness.
(5) Remove the cylinder number 1 spark plug.
(6) Hold a finger over the open spark plug hole.
Rotate the engine at the vibration dampener bolt un-
til compression (pressure) is felt.
Slowly continue to rotate the engine. Do this until
the timing index mark on the vibration damper pul-
ley aligns with the top dead center (TDC) mark (0
degree) on timing degree scale (Fig. 9). Always rotate
the engine in direction of normal rotation. Do not ro-
tate the engine backward to align the timing marks.
On XJ models equipped with A/C, remove the elec-
trical cooling fan and shroud assembly from the radi-
ator. Refer to Group 7, Cooling System for
procedures.
This will provide room to turn the engine crank-
shaft with a socket and ratchet using the vibration
damper bolt.
(7) Remove the distributor holddown bolt and
clamp (Fig. 8).
(8) Remove the distributor from engine by slowly
lifting straight up.
Note that the rotor will rotate slightly in a counter-
clockwise direction while lifting up the distributor.
The oil pump gear will also rotate slightly in a coun-terclockwise direction while lifting up the distributor.
This is due to the helical cut gears on the distributor
and camshaft.
Note the removed position of the rotor during dis-
tributor removal. During installation, this will be re-
ferred to as the Pre-position.
2.5L 4-Cylinder Engine:Observe the slot in the
oil pump gear through the hole on the side of the en-
gine. It should be slightly before (counterclockwise of)
the 10 o'clock position (Fig. 10).
4.0L 6-Cylinder Engine:Observe the slot in the
oil pump gear through the hole on the side of the en-
gine. It should be slightly before (counterclockwise of)
the 11 o'clock position (Fig. 11).
(9) Remove and discard the old distributor-to-en-
gine block gasket (Fig. 8).
INSTALLATION
(1) If the engine crankshaft has been rotated after
distributor removal, cylinder number 1 must be re-
turned to its proper firing stroke. Refer to the previ-
ous REMOVAL steps number 5 and 6. These steps
must be done before installing distributor.
Fig. 9 Align Timing Marks
Fig. 10 Slot At 10 O'clock PositionÐ2.5L Engine
Fig. 11 Slot At 11 O'clock PositionÐ4.0L Engine
8D - 20 IGNITION SYSTEMSJ

(2) Check the position of the slot on the oil pump
gear. On the 2.5L engine, it should be just slightly
before (counterclockwise of) the 10 o'clock position
(Fig. 10). On the 4.0L engine, it should be just
slightly before (counterclockwise of) the 11 o'clock po-
sition (Fig. 11). If not, place a flat blade screwdriver
into the oil pump gear and rotate it into the proper
position.
(3) Factory replacement distributors are equipped
with a plastic alignment pin already installed (Fig.
7). This pin is used to temporarily hold the rotor to
the cylinder number 1 firing position during distrib-
utor installation. If this pin is in place, proceed to
step number 8. If not, proceed to step number 4.
(4) If the original distributor is to be reinstalled,
such as during engine overhaul, the plastic pin will
not be available. A 3/16 inch drift pin punch tool may
be substituted for the plastic pin.
(5) Remove the camshaft position sensor from the
distributor housing. Lift straight up.
(6) Four different alignment holes are provided on
the plastic ring (Fig. 12).Note that 2.5L and 4.0L
engines have different alignment holes (Fig.
12).
(7) Rotate the distributor shaft and install the pin
punch tool through the proper alignment hole in the
plastic ring (Fig. 12) and into the mating access hole
in the distributor housing. This will prevent the dis-
tributor shaft and rotor from rotating.
(8) Clean the distributor mounting hole area of the
engine block.
(9) Install a new distributor-to-engine block gasket
(Fig. 8).
(10) Install the rotor to the distributor shaft.(11)2.5L 4-Cylinder Engine:Pre-position the dis-
tributor into the engine while holding the centerline
of the base slot in the 1 o'clock position (Fig. 13).
Continue to engage the distributor into the engine.
The rotor and distributor will rotate clockwise during
installation. This is due to the helical cut gears on
the distributor and camshaft. When the distributor is
fully seated to the engine block, the centerline of the
base slot should be aligned to the clamp bolt mount-
ing hole on the engine (Fig. 14). The rotor should
also be pointed slightly past (clockwise of) the 3
o'clock position.
4.0L 6-Cylinder Engine:Pre-position the distrib-
utor into the engine while holding the centerline of
the base slot in the 1 o'clock position (Fig. 13). Con-
tinue to engage the distributor into the engine. The
rotor and distributor will rotate clockwise during in-
stallation. This is due to the helical cut gears on the
distributor and camshaft. When the distributor is
fully seated to the engine block, the centerline of the
base slot should be aligned to the clamp bolt mount-
ing hole on the engine (Fig. 15). The rotor should
also be pointed at the 5 o'clock position.
It may be necessary to rotate the rotor and distrib-
utor shaft (very slightly) to engage the distributor
shaft with the slot in the oil pump gear. The same
may have to be done to engage the distributor gear
with the camshaft gear.
The distributor is correctly installed when:
²the rotor is pointed at the 3 o'clock position (2.5L
engine), or at the 5 o'clock position (4.0L engine).
²the plastic alignment pin (or pin punch tool) is still
installed to distributor.
Fig. 12 Pin Alignment HolesFig. 13 Distributor Pre-positionÐAll Engines
JIGNITION SYSTEMS 8D - 21

²the number 1 cylinder piston is set at top dead
center (TDC) (compression stroke).
²the centerline of the slot at the base of the distrib-
utor is aligned to the centerline of the distributor
holddown bolt hole on the engine. In this position,
the holddown bolt should easily pass through the slot
and into the engine.
No adjustments are necessary. Proceed to next
step.(12) Install the distributor holddown clamp and
bolt. Tighten the bolt to 23 Nzm (17 ft. lbs.) torque.
(13) Remove the pin punch tool from the distribu-
tor. Or, if the plastic alignment pin was used, remove
it straight down from the bottom of the distributor.
Discard plastic pin.
(14) If removed, install the camshaft position sen-
sor to the distributor. Align the wiring harness grom-
met to the notch in the distributor housing.
(15) Install the rotor.
CAUTION: If the distributor cap is incorrectly posi-
tioned on distributor housing, the cap or rotor may
be damaged when engine is started.
(16) Install the distributor cap. Tighten distributor
cap holddown screws to 3 Nzm (26 in. lbs.) torque.
(17) If removed, install the spark plug cables to
the distributor cap. For proper firing order, refer to
the Specifications section at the end of this group.
See Engine Firing Order.
(18) Connect the distributor wiring harness to the
main engine harness.
(19) Connect battery cable to battery.
IGNITION COIL
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
REMOVAL
On the 2.5L 4-cylinder engine, the ignition coil is
mounted to a bracket on the side of the engine (to
the rear of the distributor).
On the 4.0L 6-cylinder engine, the ignition coil is
mounted to a bracket on the side of the engine (to
the front of the distributor) (Fig. 16).
(1) Disconnect the ignition coil secondary cable
from ignition coil (Fig. 16).
(2) Disconnect engine harness connector from igni-
tion coil.
Fig. 14 Distributor Engaged PositionÐ2.5L
4-Cylinder Engine
Fig. 15 Distributor Engaged PositionÐ4.0L
6-Cylinder Engine
Fig. 16 Ignition CoilÐTypical (4.0L Shown)
8D - 22 IGNITION SYSTEMSJ

(3) Remove ignition coil mounting bolts (nuts are
used on back side of bracket). Remove coil.
INSTALLATION
(1) Install ignition coil to bracket on cylinder block
with mounting bolts and nuts.
(2) Connect engine harness connector to coil.
(3) Connect ignition coil cable to ignition coil.
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
For an operational description, diagnosis or remov-
al/ installation procedures, refer to Group 14, Fuel
Systems.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
For an operational description, diagnosis and re-
moval/installation procedures, refer to Group 14,
Fuel System.
OXYGEN (O2S) SENSOR
For an operational description, diagnosis or remov-
al/ installation procedures, refer to Group 14, Fuel
Systems.
POWERTRAIN CONTROL MODULE (PCM)
The PCM was formerly referred to as the SBEC or
engine controller.
XJ MODELS
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 17).
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Loosen 60-way connector mounting screw until
connector can be disengaged from PCM.
(3) Pull 60-way connector straight back from PCM.
(4) Remove PCM mounting bolts.
(5) Remove PCM from vehicle.INSTALLATION
(1) Check the pins in the PCM 60-way electrical
connector for damage. Repair as necessary.
(2) Install PCM. Tighten mounting bolts to 1 Nzm
(9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting screw to 4 Nzm (35 in. lbs.)
torque.
(4) Connect battery cable to battery.
YJ MODELS
On YJ models, the PCM is located in the engine
compartment behind the windshield washer fluid res-
ervoir (Fig. 18).
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Remove windshield washer fluid reservoir.
(3) Loosen 60-way connector mounting screw until
connector can be disengaged from PCM.
(4) Pull 60-way connector straight back from PCM.
(5) Remove PCM mounting bolts.
(6) Remove PCM from vehicle.
INSTALLATION
(1) Check the pins in the PCM 60-way electrical
connector for damage. Repair as necessary.
(2) Install PCM. Tighten mounting bolts to 1 Nzm
(9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting screw to 4 Nzm (35 in. lbs.)
torque.
(4) Connect battery cable to battery.
(5) Install washer fluid reservoir.
SPARK PLUGS
PLUG REMOVAL
(1) Always remove spark plug or ignition coil ca-
bles by grasping at the cable boot (Fig. 19). Turn the
cable boot 1/2 turn and pull straight back in a steady
Fig. 17 PCM LocationÐXJ Models
Fig. 18 PCM LocationÐYJ Models
JIGNITION SYSTEMS 8D - 23

motion. Never pull directly on the cable. Internal
damage to cable will result.
(2) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert.
(4) Inspect the spark plug condition. Refer to
Spark Plugs in the Diagnostics/Service Procedures
section of this group.
PLUG CLEANING
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After clean-
ing, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will re-
main on the spark plug insulator and will cause
plug misfire.
PLUG GAP ADJUSTMENT
Check the spark plug gap with a gap gauge tool. If
the gap is not correct, adjust it by bending the
ground electrode (Fig. 20).Never attempt to adjust
the gap by bending the center electrode.
SPARK PLUG GAP
²2.5L 4-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
²4.0L 6-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
PLUG INSTALLATION
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion. This may result
in a change in the spark plug gap, or a cracked por-
celain insulator.
When replacing the spark plug and ignition coil ca-
bles, route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise. It could cause cross ignition of the spark plugs,
or short circuit the cables to ground.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading.
(2) Tighten the spark plugs to 35-41 Nzm (26-30 ft.
lbs.) torque.
(3) Install spark plug cables over spark plugs.
SPARK PLUG SECONDARY CABLES
CAUTION: When disconnecting a high voltage cable
from a spark plug or from the distributor cap, twist
the rubber boot slightly (1/2 turn) to break it loose
(Fig. 19). Grasp the boot (not the cable) and pull it
off with a steady, even force.
Install cables into the proper engine cylinder firing
order (Figs. 21 or 22).
When replacing the spark plug and coil cables,
route the cables correctly and secure in the proper
retainers. Failure to route the cables properly can
cause the radio to reproduce ignition noise. It could
also cause cross ignition of the plugs, or short circuit
the cables to ground.
Fig. 19 Cable Removal
Fig. 20 Setting Spark Plug GapÐTypical
8D - 24 IGNITION SYSTEMSJ

When installing new cables, make sure a positive
connection is made. A snap should be felt when a
good connection is made between the plug cable and
the distributor cap tower.THROTTLE POSITION SENSOR (TPS)
For an operational description, diagnosis and re-
moval/installation procedures, refer to Group 14,
Fuel System.
Fig. 22 Engine Firing OrderÐ4.0L 6-Cylinder EngineFig. 21 Engine Firing OrderÐ2.5L 4-Cylinder Engine
JIGNITION SYSTEMS 8D - 25

IGNITION SWITCHÐXJ MODELS
IGNITION SWITCH AND KEY CYLINDER SERVICE
The ignition switch is located on the steering col-
umn. The Key-In-Switch and Halo Light are integral
with the ignition switch. Refer to Group 8U for Key-
In-Switch and Halo Light diagnosis for XJ models.
Refer to Group 8W, Wiring for ignition switch wir-
ing circuits.
REMOVAL
(1) Disconnect negative battery cable from battery.
(2) If vehicle has a tilt column, remove tilt lever by
turning it counterclockwise.
(3) Remove upper and lower covers from steering
column (Fig. 1).
(4) Remove ignition switch mounting screws. Use
tamper proof torx bit Snap-on TTXR20A2 or equiva-
lent to remove the screws (Fig. 2 or 3).
(5) Gently pull switch away from column. Release
connector locks on 7-terminal wiring connector, then
remove connector from ignition switch.
(6) Release connector lock on 4-terminal connector,
then remove connector from ignition switch (Fig. 4).
(7) To remove key cylinder from ignition switch:
(a) Insert key in ignition switch. Turn key to
LOCK position. Using a TTXR20A2 or equivalent
torx bit, remove key cylinder retaining screw and
bracket (Fig. 5 or 6).
(b) Rotate key clockwise to the OFF position.
Key cylinder will unseat from ignition switch (Fig.
7). When key cylinder is unseated, it will be ap-proximately 1/8 inch away from ignition switch
halo light ring.Do not attempt to remove key
cylinder at this time.
(c) With key cylinder in unseated position, rotate
key counterclockwise to the lock position and re-
move key.
(d) Remove key cylinder from ignition switch
(Fig. 8).
Fig. 1 Shroud Removal/InstallationÐTypical
Fig. 2 Ignition Switch Screw Removal
Fig. 3 Ignition Switch Screw Removal
8D - 26 IGNITION SYSTEMSJ

INSTALLATION
(1) Connect electrical connectors to ignition switch.
Make sure that switch locking tabs are fully seated
in wiring connectors.
(2) Before attaching ignition switch to a tilt steer-
ing column, the transmission shifter must be in Park
position. The park lock dowel pin and column lock
flag must also be properly indexed before installing
switch (Fig. 9).
(a) Place transmission shifter in PARK position.
(b) Place ignition switch in lock position. The
switch is in the lock position when column lock flag
is parallel to ignition switch terminals (Fig. 9).
(c) Position ignition switch park lock dowel pin
so it will engage steering column park lock slider
linkage (Fig. 10).(d) Apply a light coating of grease to column lock
flag and park lock dowel pin.
(3) Place ignition switch against lock housing open-
ing on steering column. Ensure that ignition switch
park lock dowel pin enters slot in park lock slider
linkage in steering column.
(4) Install retaining bracket and ignition switch
mounting screws. Tighten screws to 36.5 Nzm (2664
in. lbs.) torque.
(5) Install ignition lock cylinder:
Fig. 4 Key-In-Switch and Halo Lamp Connector
Fig. 5 Key Cylinder Retaining Screw
Fig. 6 Key Cylinder Retaining Screw
Fig. 7 Unseated Key Cylinder
JIGNITION SYSTEMS 8D - 27

(a) With lock cylinder and ignition switch in
Lock position, insert lock cylinder into ignition
switch until it bottoms.(b) Insert ignition key into lock cylinder. While
gently pushing lock cylinder in toward ignition
switch, rotate ignition key to end of travel.
(6) Install retaining screw into bracket and lock
cylinder. Tighten screw to 36.5 Nzm (2664 in. lbs.)
torque.
(7) Install steering column covers. Tighten screws
to2Nzm (17 in. lbs.) torque.
(8) If vehicle is equipped with a tilt steering col-
umn, install tilt lever.
(9) Connect negative cable to battery.
(10) Check for proper operation of halo light, shift
lock (if applicable), and column lock. Also check for
proper operation of ignition switch accessory, lock,
off, run, and start positions.
Fig. 10 Ignition Switch Mounting PadFig. 8 Key Cylinder Removal
Fig. 9 Ignition Switch View From Column
8D - 28 IGNITION SYSTEMSJ

IGNITION SWITCHÐYJ MODELS
GENERAL INFORMATION
This section will cover the electrical portion
of the ignition switch. To service the mechani-
cal ignition key switch, refer to Group 19,
Steering.
Refer to Group 8W, Wiring for ignition switch wir-
ing circuits.
The ignition switch is mounted under the instru-
ment panel on the lower section of the steering col-
umn. The headlamp dimmer switch is mounted
beside the ignition switch (Fig. 11). Both of these
switches (ignition and dimmer) share the same
mounting screws.
The switch is connected to the ignition key lock as-
sembly by a remote actuator rod. This remote actua-
tor rod fits into an access hole on the bottom of the
ignition switch (Fig. 12).
REMOVAL
(1) Disconnect the negative battery cable at the
battery.
(2) Remove the windshield wiper intermittent con-
trol module and its bracket (if equipped).
(3) Place the ignition key lock in ACCESSORY po-
sition.
(4) Remove the two headlamp dimmer switch at-
taching nuts. Lift the switch from steering column
while disengaging actuator rod.
Before removing dimmer switch, tape the two
remote control actuator rods (ignition switchand dimmer) to the steering column. This will
prevent accidental disengagement from the up-
per part of the steering column.
(5) Remove the ignition switch-to-steering column
attaching screws.
(6) Disengage the ignition switch from the remote
actuator rod by lifting straight up. Remove switch
from steering column.
(7) Remove wiring from switch as follows:
Two electrical connectors are used to connect all
wiring to the ignition switch. One of the connectors is
installed (interlocked) over the top of the other con-
nector. Remove wiring from switch by disconnecting
the (black) harness connector first and then the other
connector. Remove the switch from the vehicle.
SWITCH TESTING
To test the ignition switch circuity and continuity,
proceed as follows. Place the slide bar (on the igni-
tion switch) (Fig. 12) into the detent position to be
tested. An ohmmeter or continuity light may be used
to check switch continuity. Refer to the Ignition
Switch Continuity Tests chart for continuity tests.
Refer to (Fig. 13) for the lettered/numbered terminal
positions.All wiring must be disconnected from
the ignition switch before performing any con-
tinuity testing.
There are five positions on the ignition switch. The
switch positions (in order) are: ACCESSORY, OFF-
LOCK, OFF, ON AND START (Figs. 14 or 15). Each
position has a detent stop (except START), which isFig. 11 Ignition Switch/Headlamp Dimmer SwitchÐ
Typical
Fig. 12 Ignition Switch/Remote Actuator RodÐ
Typical
JIGNITION SYSTEMS 8D - 29