1994 JEEP CHEROKEE battery

ENGINE DIAGNOSIS
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine tune-ups.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or me-
chanical (e.g., a strange noise).
Refer to the Service DiagnosisÐPerformance chart
and the Service DiagnosisÐMechanical chart for pos-
sible causes and corrections of malfunctions. Refer to
Group 14, Fuel System for the fuel system diagnosis.
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts. In-
formation concerning additional tests and diagnosis
is provided within the following diagnosis:
²Cylinder Compression Pressure Test.
²Cylinder Combustion Pressure Leakage Test.
²Engine Cylinder Head Gasket Failure Diagnosis.
²Intake Manifold Leakage Diagnosis.
INTAKE MANIFOLD LEAKAGE DIAGNOSIS
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A DI-
RECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
METHOD 1
(1) Start the engine.
(2) Open the acetylene valve of an oxyacetylene
torch. DO NOT ignite.
(3) Pass the torch tip over the exposed gasket area
(EDGE) between the manifold and the engine cylin-
der head.
(4) If the engine speed increases, the manifold has
an air leak.
METHOD 2
(1) Start the engine.
(2) Apply engine oil to the exposed gasket area
(EDGE) between the manifold and the engine cylin-
der head.
(3) If oil is forced into the manifold and if smoke is
visible from the exhaust tailpipe, the manifold has
an air leak.
CYLINDER COMPRESSION PRESSURE TEST
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cyl-
inders.
Refer to Engine Specifications for the correct en-
gine compression pressures.
ENGINE CYLINDER HEAD GASKET FAILURE
DIAGNOSIS
A leaking engine cylinder head gasket usually re-
sults in loss of power, loss of coolant and engine mis-
firing.
An engine cylinder head gasket leak can be located
between adjacent cylinders or between a cylinder and
the adjacent water jacket.
²An engine cylinder head gasket leaking between
adjacent cylinders is indicated by a loss of power
and/or engine misfire.
²An engine cylinder head gasket leaking between a
cylinder and an adjacent water jacket is indicated by
coolant foaming or overheating and loss of coolant.
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders; follow the proce-
dures outlined in Cylinder Compression Pressure
Test. An engine cylinder head gasket leaking be-
tween adjacent cylinders will result in approximately
a 50-70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE
TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A DI-
RECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
Remove the radiator cap.
Start the engine and allow it to warm up until the
engine thermostat opens.
If a large combustion/compression pressure leak ex-
ists, bubbles will be visible in the coolant.
If bubbles are not visible, install a radiator pres-
sure tester and pressurize the coolant system.
JENGINES 9 - 5

The digits of the code identify:
(1) 1st DigitÐThe year (4 = 1994).
(2) 2nd & 3rd DigitsÐThe month (01 - 12).
(3) 4th & 5th DigitsÐThe engine type/fuel system/
compression ratio (HX = A 2.5 liter (150 CID) 9.1:1
compression ratio engine with a multi-point fuel in-
jection system).
(4) 6th & 7th DigitsÐThe day of engine build (01 -
31).
FOR EXAMPLE:Code * 401HX23 * identifies a
2.5 liter (150 CID) engine with a multi-point fuel in-
jection system, 9.1:1 compression ratio and built on
January 23, 1994.
OVERSIZE AND UNDERSIZE COMPONENT
CODES
Some engines may be built with oversize or under-
size components such as:
²Oversize cylinder bores.
²Oversize camshaft bearing bores.
²Undersize crankshaft main bearing journals.
²Undersize connecting rod journals.
These engines are identified by a letter code (Fig.
4) stamped on the oil filter boss near the distributor
(Fig. 5).
ENGINE MOUNTSÐFRONT
The front mounts support the engine at each side.
These supports are made of resilient rubber.
REMOVALÐXJ VEHICLES
(1) Disconnect negative cable from battery.
(2) Raise the vehicle.
(3) Support the engine.
(4) Remove through bolt nut (Fig. 6). DO NOT re-
move the through bolt.
(5) Remove the retaining bolts/nuts from the sup-
port cushions (Fig. 6).
(6) Remove the through bolt.
(7) Remove the support cushions.
INSTALLATIONÐXJ VEHICLES
(1) If the engine support bracket was removed, po-
sition the LEFT bracket (Fig. 6) and the RIGHT
bracket with generator brace (Fig. 7) onto the cylin-
der block. Install the bolts and stud nuts.
(a) RIGHT SIDE (Fig. 7)ÐTighten the bolts to
61 Nzm (45 ft. lbs.) torque. Tighten the stud nuts to
46 Nzm (34 ft. lbs.) torque.
(b) LEFT SIDE (Fig. 6)ÐTighten the bolts to 61
Nzm (45 ft. lbs.) torque.
(2) If the support cushion brackets were removed,
position the brackets onto the lower front sill (Figs. 6
and 8). Install the bolts and stud nuts. Tighten the
bolts to 54 Nzm (40 ft. lbs.) torque and the stud nuts
to 41 Nzm (30 ft. lbs.) torque.
(3) Place the support cushions onto the support
cushion brackets (Fig. 6). Tighten the right support
cushion nuts to 65 Nzm (48 ft. lbs.) torque. Tighten
the left support cushion bolt/nut to 41 Nzm (30 ft.
lbs.) torque.
Fig. 4 Oversize and Undersize Component Codes
Fig. 5 Oversize and Undersize Component Code
Location
9 - 10 2.5L ENGINEJ

(4) Install the through bolt and the retaining nut
(Fig. 6). Tighten the through bolt nut to 65 Nzm (48
ft. lbs.) torque.
(5) Remove the engine support.
(6) Lower the vehicle.
(7) Connect negative cable to battery.
REMOVALÐYJ VEHICLES
(1) Disconnect negative cable from battery.
(2) Raise the vehicle.(3) Support the engine.
(4) Remove through bolt nut (Fig. 9). DO NOT re-
move the through bolt.
(5) Remove the retaining bolts/nuts from the sup-
port cushions (Fig. 9).
(6) Remove the through bolt.
(7) Remove the engine support cushions.
Fig. 6 Front MountsÐXJ Vehicles
Fig. 7 Engine Support BracketÐRight Side
Fig. 8 Support Cushion BracketÐLeft Side
Fig. 9 Front MountsÐYJ Vehicles
J2.5L ENGINE 9 - 11

INSTALLATIONÐYJ VEHICLES
(1) If the engine support bracket was removed, po-
sition the bracket onto the block and install the at-
taching bolts (Fig. 9). Tighten the bolts to 62 Nzm
(46 ft. lbs.) torque.
(2) Place the support cushion on the support cush-
ion bracket (Fig. 9). Install the support cushion re-
taining bolts and nuts. Tighten the bolts/nuts to 52
Nzm (38 ft. lbs.) torque.
(3) Install the through bolt and the retaining nut
(Fig. 9). Tighten the through bolt nut to 69 Nzm (51
ft. lbs.) torque.
(4) Remove the engine support.
(5) Lower the vehicle.
(6) Connect negative cable to battery.
ENGINE MOUNTÐREAR
A resilient rubber cushion supports the transmis-
sion at the rear between the transmission extension
housing and the rear support crossmember or skid
plate.
REMOVALÐXJ VEHICLES
(1) Disconnect negative cable from battery.
(2) Raise the vehicle and support the transmission.
(3) Remove the nuts holding the support cushion to
the crossmember (Figs. 10 and 11). Remove the cross-
member.
(4)MANUAL TRANSMISSION:
(a) Remove the support cushion nuts and remove
the cushion.
(b) If necessary, remove the bolts holding the
transmission support bracket to the transmission
(Fig. 10). Remove the bracket.
(5)AUTOMATIC TRANSMISSION:
(a) Remove the support cushion bolts and remove
the cushion and the transmission support bracket.(b) If necessary on 2WD vehicles, remove the
bolts holding the transmission support adaptor
bracket to the transmission (Fig. 11). Remove the
adaptor bracket.
INSTALLATIONÐXJ VEHICLES
(1)MANUAL TRANSMISSION:
(a) If removed, position the transmission support
bracket to the transmission and install the bolts.
Tighten the bolts to 43 Nzm (32 ft. lbs.) torque.
(b) Position the support cushion onto the trans-
mission support bracket. Install and tighten the
nuts to 46 Nzm (34 ft. lbs.) torque.
(2)AUTOMATIC TRANSMISSON:
(a) If removed, position the transmission support
adaptor bracket (2WD vehicles) to the transmission
and install the bolts. Tighten the bolts to 75 Nzm
(55 ft. lbs.) torque.
(b) Position the transmission support bracket
and support cushion to the transmission and install
the bolts. Tighten the bolts to 75 Nzm (55 ft. lbs.)
torque.
(3) Position the crossmember onto the support
cushion studs and install the nuts. Tighten the nuts
to 22 Nzm (192 in. lbs.) torque.
(4) Install the crossmember to sill bolts and
tighten to 41 Nzm (30 ft. lbs.) torque.
Fig. 10 Rear MountÐXJ Vehicles (Manual
Transmission)
Fig. 11 Rear MountÐXJ Vehicles (Automatic
Transmission)
9 - 12 2.5L ENGINEJ

(5) Remove the transmission support.
(6) Lower the vehicle.
(7) Connect negative cable to battery.
REMOVALÐYJ VEHICLES
(1) Disconnect negative cable from battery.
(2) Raise the vehicle and support the transmission.
(3) Remove the nuts holding the support cushion to
the skid plate (Figs. 12 and 13).
(4) Remove the skid plate bolts and the skid plate.
(5)MANUAL TRANSMISSION:
(a) Remove the bolts holding the support cushion
and torque arm bracket to the transmission (Fig.
12).
(b) Remove the support cushion and torque arm
bracket.
(6)AUTOMATIC TRANSMISSION:
(a) Remove the bolts and nuts holding the sup-
port cushinon to the torque arm bracket (Fig 13).
Remove the support cushion.
(b) Remove the bolts holding the torque arm
bracket to the transmission (Fig. 13). Remove the
torque arm bracket.
INSTALLATIONÐYJ VEHICLES
(1)MANUAL TRANSMISSION:
(a) Position the torque arm bracket and support
cushion to the transmission and install the bolts
(Fig. 12).
(b) Tighten the bolts to 54 Nzm (40 ft. lbs.)
torque.
(2)AUTOMATIC TRANSMISSION:
(a) Position the torque arm bracket to the trans-
mission and install the bolts. Tighten the bolts to
54 Nzm (40 ft. lbs.) torque.
(b) Position the support cushion to the torque
arm bracket and install the bolts and nuts. Tighten
the nuts to 54 Nzm(40 ft. lbs.) torque.(3) Position the skid plate to the studs of the sup-
port cushion and install the nuts (Figs. 12 and 13).
Tighten the stud nuts to 54 Nzm (40 ft. lbs.) torque.
(4) Install the skid plate bolts to the sill and
tighten to 88 Nzm (65 ft. lbs.) torque.
(5) Remove the transmission support.
(6) Lower the vehicle.
(7) Connect negative cable to battery.
ENGINE DAMPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the top and bottom damper nuts (Fig.
14).
(3) Remove the outer retainers and bushings (Fig.
14).
(4) Remove the top damper bracket nut and bolts
(Fig. 14).
(5) Remove the bracket, inner retainers, bushings
and the damper (Fig. 14).
INSTALLATION
(1) Install the damper on the lower bracket with
the lower inner retainer and bushing in place.
Fig. 12 Rear MountÐYJ Vehicles (Manual
Transmission)
Fig. 13 Rear MountÐYJ Vehicles (Automatic
Transmission)
J2.5L ENGINE 9 - 13

(2) Install the upper inner retainer and bushing on
the top of the damper.
(3) Position the upper damper bracket over the
damper and install the stud nut and bolts.
(4) Tighten the stud nut to 23 Nzm (17 ft. lbs.)
torque. Tighten the bracket bolts to 61 Nzm (45 ft.
lbs.) torque.
(5) Install the bushing, upper outer retainer and
damper nut.
(6) Install the bushing, lower outer retainer and
damper nut.
(7) Tighten the upper and lower damper nuts.
(8) Connect negative cable to battery.
ENGINE ASSEMBLYÐXJ VEHICLES
REMOVAL
(1) Disconnect the battery cables. Remove the bat-
tery.
(2) Mark the hinge locations on the hood panel for
alignment reference during installation. Remove the
engine compartment lamp. Remove the hood.
WARNING: THE COOLANT IN A RECENTLY OPER-
ATED ENGINE IS HOT AND PRESSURIZED. USE
CARE TO PREVENT SCALDING BY HOT COOLANT.
CAREFULLY RELEASE THE PRESSURE BEFORE
REMOVING THE RADIATOR DRAIN COCK AND
CAP.(3) Remove the radiator drain cock and radiator
cap to drain the coolant. DO NOT waste usable cool-
ant. If the solution is clean, drain the coolant into a
clean container for reuse.
(4) Remove the lower radiator hose.
(5) Remove the upper radiator hose and coolant re-
covery hose (Fig. 15).
(6) Remove the fan shroud (Fig. 15).
(7) Disconnect the transmission fluid cooler tubing
(automatic transmission).
(8) Remove the radiator/condenser (if equipped
with air conditioning).
(9) Remove fan assembly and install a 5/16 x 1/2-
inch SAE capscrew through fan pulley into water
pump flange. This will maintain the pulley and wa-
ter pump in alignment when crankshaft is rotated.
(10) Disconnect the heater hoses (Figs. 16 and 17).
(11) Disconnect the throttle linkages (Fig. 16),
speed control cable (if equipped) and throttle valve
rod.
(12) Disconnect the oxygen sensor wire connector.
(13) Disconnect the wires from the starter motor
solenoid.
(14) Disconnect all fuel injection harness connec-
tions.
(15) Disconnect the quick-connect fuel lines at the
fuel rail and return line by squeezing the two retain-
ing tabs against the fuel tube (Fig. 16). Pull the fuel
tube and retainer from the quick-connect fitting (re-
fer to Group 14, Fuel System for the proper proce-
dure).
(16) Remove the fuel line bracket from the intake
manifold.
(17) Remove the air cleaner assembly (Fig. 18).
(18) If equipped with air conditioning, remove the
service valves and cap the compressor ports.
(19) Remove the power brake vacuum check valve
from the booster, if equipped.
(20) If equipped with power steering (Fig. 18):
Fig. 14 Engine Damper
Fig. 15 Upper Radiator Hose, Coolant Recovery
Hose & Fan Shroud
9 - 14 2.5L ENGINEJ

(a) Align the transmission torque converter
housing with the engine.
(b) Loosely install the converter housing lower
bolts and install the next higher bolt and nut on
each side.
(c) Tighten all 4 bolts finger-tight.
(5) Install the engine support cushions (if re-
moved).
(6) Lower the engine and engine support cushions
onto the engine compartment brackets.
(7) Remove the engine lifting device.
(8) Raise the vehicle.
(9) If equipped with an automatic transmission:
(a) Install the converter-to-drive plate bolts. En-
sure the installation reference marks are aligned.
Tighten the bolts to 54 Nzm (40 ft. lbs.) torque.
(b) Install the converter-housing access cover.
(c) Install the exhaust pipe support.
(10) Install the remaining converter or flywheel
housing bolts.
(11) Install the starter motor and connect the ca-
ble. Tighten the bolts to 45 Nzm (33 ft. lbs.) torque.
(12) Tighten the engine support cushing through-
bolt nuts.
(13) Install the remaining flywheel/converter hous-
ing bolts. Tighten the bolts to 38 Nzm (28 ft. lbs.)
torque.
(14) Connect the exhaust pipe to the manifold.
(15) Install the oil filter.
(16) Lower the vehicle.
(17) Connect the coolant hoses and tighten the
clamps.
(18) If equipped with power steering:
(a) Remove the protective caps
(b) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 Nzm (38 ft. lbs.)
torque.
(c) Fill the pump reservoir with fluid.
(19) Remove the pulley-to-water pump flange
alignment capscrew and install the fan and spacer or
Tempatrol fan assembly.
(20) Install the fan shroud and radiator/condenser
(if equipped with air conditioning).
(21) Connect the radiator hoses.
(22) Connect the automatic transmission fluid
cooler pipes, if equipped.
(23) Connect the oxygen sensor wire connector.
(24) Connect the throttle valve rod and retainer.
Connect the throttle cable and install the rod. Install
the throttle valve rod spring.
(25) Connect the speed control cable, if equipped.
(26) Connect the fuel supply and return lines to
the throttle body.
(27) Connect all the vacuum hoses and wire con-
nectors.
(28) Connect the service valves to the A/C com-
pressor ports, if equipped with air conditioning.(29) Fill the power steering reservoir.
(30) Connect the battery cables.
(31) Install the hood.
(32) Install the air cleaner.
(33) Start the engine and inspect for leaks.
(34) Fill the cooling system.
(35) Stop the engine and check the fluid levels.
Add fluid, as required.
ENGINE ASSEMBLYÐYJ VEHICLES
REMOVAL
(1) Place a protective cloth over the windshield
frame. Raise the hood and rest it on the windshield
frame (Fig. 19).
(2) Disconnect the battery cable clamps and re-
move the battery.
WARNING: THE COOLANT IN A RECENTLY OPER-
ATED ENGINE IS HOT AND PRESSURIZED. USE
CARE TO PREVENT SCALDING BY HOT COOLANT.
CAREFULLY RELEASE THE PRESSURE BEFORE
REMOVING THE RADIATOR DRAIN COCK AND
CAP.
(3) Remove the radiator drain cock and radiator
cap to drain the coolant. DO NOT waste usable cool-
ant. If the solution is clean, drain the coolant into a
clean container for reuse.
(4) Disconnect the wire connectors from the gener-
ator.
(5) Disconnect the ignition coil and distributor
wire connectors.
(6) Disconnect the oil pressure sender wire connec-
tor.
Fig. 19 Hood on Windshield Frame
9 - 16 2.5L ENGINEJ

(14) Install the remaining flywheel housing bolts.
Tighten the bolts to 38 Nzm (28 ft. lbs.) torque.
(15) Install the starter motor and connect the ca-
ble. Tighten the bolts to 45 Nzm (33 ft. lbs.) torque.
(16) Install the oil filter.
(17) Lower the vehicle.
(18) Connect the coolant hoses and tighten the
clamps.
(19) If equipped with power steering:
(a) Remove the protective caps
(b) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 Nzm (38 ft. lbs.)
torque.
(c) Fill the pump reservoir with fluid.
(20) Remove the pulley-to-water pump flange
alignment capscrew and install the fan and spacer or
Tempatrol fan assembly.
(21) Tighten the serpentine drive belt according to
the specifications listed in Group 7, Cooling System.
(22) Install the fan shroud and radiator.
(23) Connect the radiator hoses.
(24) Connect the heater hoses.
(25) Connect the throttle valve rod and retainer.
(26) Connect the throttle cable and install the rod.
(27) Install the throttle valve rod spring.
(28) Connect the speed control cable, if equipped.
(29) Connect the oxygen sensor wire connector.
(30) Install the vacuum hose and check valve on
the brake booster.
(31) Connect the coolant temperature sensor wire
connector.
(32) Connect the idle speed actuator wire connec-
tor.
(33) Connect the fuel inlet and return hoses at the
fuel rail. Verify that the quick-connect fitting assem-
bly fits securely over the fuel lines by giving the fuel
lines a firm tug.
(34) Install the fuel line bracket to the intake
manifold.
(35) Connect all fuel injection wire connections.
(36) Install the engine ground strap.
(37) Connect the ignition coil wire connector.
(38) Remove the coolant temperature sending unit
to permit air to escape from the block. Fill the cool-
ing system with coolant. Install the coolant tempera-
ture sending unit when the system is filled.
(39) Install the battery and connect the battery ca-
bles.
(40) Install the air cleaner bonnet to the throttle
body.
(41) Install the air cleaner.
(42) Lower the hood and secure in place.
(43) Start the engine and inspect for leaks.
(44) Stop the engine and check the fluid levels.
Add fluid, as required.ENGINE CYLINDER HEAD COVER
A cured gasket is part of the engine cylinder head
cover.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect the Crankcase Ventilation (CCV)
vacuum hose from engine cylinder head cover (Fig.
1).
(3) Disconnect the fresh air inlet hose from the en-
gine cylinder head cover (Fig. 1).
(4) Remove the engine cylinder head cover mount-
ing bolts.
(5) Remove the engine cylinder head cover.
CLEANING
Remove any original sealer from the cover sealing
surface of the engine cylinder head and clean the
surface using a fabric cleaner.
Remove all residue from the sealing surface using
a clean, dry cloth.
INSPECTION
Inspect the engine cylinder head cover for cracks.
Replace the cover, if cracked.
The original grey gasket material should NOT be
removed. If sections of the gasket material are miss-
ing or are compressed, replace the engine cylinder
head cover. However, sections with minor damage
such as small cracks, cuts or chips may be repaired
with a hand held applicator. The new material must
be smoothed over to maintain gasket height. Allow
the gasket material to cure prior to engine cylinder
head cover installation.
INSTALLATION
(1) If a replacement cover is installed, transfer the
CCV valve grommet the oil filler cap from the origi-
nal cover to the replacement cover.
(2) Install engine cylinder head cover. Tighten the
mounting bolts to 10 Nzm (85 in. lbs.) torque.
Fig. 1 Engine Cylinder Head Cover
9 - 18 2.5L ENGINEJ