Fuel system JEEP GRAND CHEROKEE 2002 WJ / 2.G Owner's Manual

WIRING
TABLE OF CONTENTS
page page
WIRING DIAGRAM INFORMATION....... 8W-01-1
COMPONENT INDEX.................. 8W-02-1
POWER DISTRIBUTION............... 8W-10-1
JUNCTION BLOCK.................... 8W-12-1
GROUND DISTRIBUTION.............. 8W-15-1
BUS COMMUNICATIONS.............. 8W-18-1
CHARGING SYSTEM.................. 8W-20-1
STARTING SYSTEM.................. 8W-21-1
FUEL/IGNITION SYSTEM.............. 8W-30-1
TRANSMISSION CONTROL SYSTEM..... 8W-31-1
VEHICLE SPEED CONTROL............ 8W-33-1
ANTILOCK BRAKES................... 8W-35-1
VEHICLE THEFT SECURITY SYSTEM..... 8W-39-1
INSTRUMENT CLUSTER............... 8W-40-1
HORN/CIGAR LIGHTER/POWER OUTLET . . 8W-41-1
AIR CONDITIONING-HEATER........... 8W-42-1
AIRBAG SYSTEM.................... 8W-43-1
INTERIOR LIGHTING.................. 8W-44-1
BODY CONTROL MODULE............. 8W-45-1AUDIO SYSTEM..................... 8W-47-1
REAR WINDOW DEFOGGER............ 8W-48-1
OVERHEAD CONSOLE................. 8W-49-1
FRONT LIGHTING.................... 8W-50-1
REAR LIGHTING..................... 8W-51-1
TURN SIGNALS...................... 8W-52-1
WIPERS............................ 8W-53-1
TRAILER TOW....................... 8W-54-1
POWER WINDOWS................... 8W-60-1
POWER DOOR LOCKS................ 8W-61-1
POWER MIRRORS................... 8W-62-1
POWER SEATS...................... 8W-63-1
POWER SUNROOF................... 8W-64-1
SPLICE INFORMATION................ 8W-70-1
CONNECTOR PIN-OUT................ 8W-80-1
CONNECTOR/GROUND/SPLICE
LOCATION........................ 8W-91-1
POWER DISTRIBUTION............... 8W-97-1 WJWIRING 8W - 1

8W-30 FUEL/IGNITION SYSTEM
Component Page
A/C Compressor Clutch Relay . . . 8W-30-23, 35, 39, 41, 42
A/C Pressure Transducer........ 8W-30-21, 42, 45, 31
Accelerator Pedal Position Sensor........ 8W-30-37, 48
Adjustable Pedals Module................ 8W-30-33
Adjustable Pedals Motor/Sensor Assembly.... 8W-30-33
Adjustable Pedals Switch................ 8W-30-33
Auto Shut Down Relay...... 8W-30-8, 9, 12, 24, 25, 26,
27, 28, 29, 30, 35, 39, 41
Battery Temperature Sensor.......... 8W-30-2, 11, 50
Body Control Module................... 8W-30-46
Boost Pressure Sensor.................. 8W-30-45
Brake Lamp Switch.............. 8W-30-4, 5, 32, 51
Camshaft Position Sensor........ 8W-30-18, 19, 20, 49
Capacitor........................... 8W-30-12
Capacitor No. 1....................... 8W-30-16
Capacitor No. 2....................... 8W-30-17
Clockspring...................... 8W-30-4, 5, 38
Coil On Plug No. 1.................... 8W-30-17
Coil On Plug No. 2.................... 8W-30-16
Coil On Plug No. 3.................... 8W-30-17
Coil On Plug No. 4.................... 8W-30-16
Coil On Plug No. 5.................... 8W-30-17
Coil On Plug No. 6.................... 8W-30-16
Coil On Plug No. 7.................... 8W-30-17
Coil On Plug No. 8.................... 8W-30-16
Coil Rail............................ 8W-30-12
Controller Antilock Brake........... 8W-30-2, 36, 51
Crankcase Heater..................... 8W-30-35
Crankshaft Position Sensor....... 8W-30-18, 19, 20, 49
Data Link Connector............... 8W-30-6, 7, 46
Diagnostic Junction Port.......... 8W-30-6, 7, 33, 46
EGR Solenoid........................ 8W-30-50
Electronic Speed Control Servo........... 8W-30-4, 5
Engine Control Module.... 8W-30-34, 35, 36, 37, 38, 39,
40, 41, 42, 43, 44, 45,
46, 47, 48, 49, 50, 51
Engine Coolant Temperature Sensor . . . 8W-30-21, 22, 47
Engine Oil Pressure Sensor......... 8W-30-21, 22, 45
Engine Starter Motor Relay......... 8W-30-18, 19, 39
EVAP/Purge Solenoid.................. 8W-30-4, 5
Fuel Injector No. 1............... 8W-30-13, 15, 44
Fuel Injector No. 2............... 8W-30-13, 14, 44
Fuel Injector No. 3............... 8W-30-13, 15, 44
Fuel Injector No. 4............... 8W-30-13, 14, 44
Fuel Injector No. 5............... 8W-30-13, 15, 44
Fuel Injector No. 6.................. 8W-30-13, 14
Fuel Injector No. 7..................... 8W-30-15
Fuel Injector No. 8..................... 8W-30-14
Fuel Pressure Sensor................... 8W-30-37
Fuel Pressure Solenoid.................. 8W-30-47
Fuel Pump Module.................... 8W-30-10
Fuel Pump Relay.................. 8W-30-8, 9, 10
Fuel Tank Module..................... 8W-30-45
Fuse 6........................... 8W-30-8, 42
Fuse 10............................ 8W-30-33
Fuse 11............................ 8W-30-43
Fuse 12......................... 8W-30-8, 9, 40
Fuse 13............................ 8W-30-41
Fuse 16 . . 8W-30-24, 25, 26, 27, 28, 29, 30, 35, 37, 39, 41
Component Page
Fuse 19............................. 8W-30-9
Fuse 21......................... 8W-30-4, 5, 32
Fuse 22............................ 8W-30-34
Fuse 23............................ 8W-30-39
Fuse 24............................. 8W-30-9
Fuse 26..................... 8W-30-8, 12, 41, 47
Fuse 31............................ 8W-30-39
G103....................... 8W-30-8, 34, 39, 46
G104......................... 8W-30-26, 27, 30
G105........................... 8W-30-35, 39
G108........................... 8W-30-23, 43
G123.............................. 8W-30-50
G300............................ 8W-30-4, 33
G301............................ 8W-30-5, 10
Generator...................... 8W-30-3, 23, 35
Glow Plug No. 1...................... 8W-30-42
Glow Plug No. 2...................... 8W-30-43
Glow Plug No. 3...................... 8W-30-42
Glow Plug No. 4...................... 8W-30-43
Glow Plug No. 5...................... 8W-30-42
Glow Plug Relay No. 1............. 8W-30-35, 42, 43
Glow Plug Relay No. 2............. 8W-30-35, 42, 43
Hydraulic Cooling Module . . . 8W-30-3, 24, 25, 30, 31, 43
Idle Air Control Motor.................. 8W-30-20
Intake Air Temperature Sensor....... 8W-30-21, 22, 38
Intake Port Swirl Actuator............... 8W-30-39
Junction Block......... 8W-30-4, 5, 8, 9, 32, 33, 39, 40
Knock Sensor........................ 8W-30-11
Leak Detection Pump................... 8W-30-23
Manifold Absolute Pressure Sensor.... 8W-30-20, 21, 22
Mass Air Flow Sensor.................. 8W-30-37
Output Speed Sensor.................... 8W-30-2
Oxygen Sensor 1/1 Upstream...... 8W-30-25, 26, 28, 29
Oxygen Sensor 1/2 Downstream.... 8W-30-24, 25, 26, 30
Oxygen Sensor 2/1 Upstream........ 8W-30-27, 28, 29
Oxygen Sensor 2/2 Downstream...... 8W-30-24, 27, 30
Oxygen Sensor Downstream Relay . . 8W-30-24, 26, 27, 30
Park/Neutral Position Switch............. 8W-30-33
Power Distribution Center...... 8W-30-8, 9, 12, 24, 25,
26, 27, 28, 29, 30, 34, 35,
37, 39, 41, 42, 43, 47
Powertrain Control Module . . . 8W-30-2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17,
18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 31, 32
Shifter Assembly............... 8W-30-2, 32, 38, 40
Speed Control Switch No. 1........... 8W-30-4, 5, 38
Speed Control Switch No. 2........... 8W-30-4, 5, 38
Throttle Position Sensor................. 8W-30-20
Transfer Case Position Sensor........... 8W-30-8, 51
Transmission Control
Module............. 8W-30-6, 7, 20, 23, 32, 36, 40
Transmission Control Relay.............. 8W-30-23
Transmission Solenoid................ 8W-30-3, 21
Transmission Solenoid/TRS Assembly....... 8W-30-33
Viscous/Cabin Heater................... 8W-30-39
Viscous/Cabin Heater Relay...... 8W-30-35, 39, 41, 42
Wastegate Solenoid.................... 8W-30-35
Water In Fuel Sensor................... 8W-30-50
WJ8W-30 FUEL/IGNITION SYSTEM 8W - 30 - 1

8W-31 TRANSMISSION CONTROL SYSTEM
Component Page
Auto Shut Down Relay................ 8W-31-4
Back-Up Lamp Relay................ 8W-31-15
Body Control Module................ 8W-31-14
Brake Lamp Switch............... 8W-31-14, 15
Controller Antilock Brake............. 8W-31-17
Crankshaft Position Sensor.......... 8W-31-9, 10
Data Link Connector............ 8W-31-9, 10, 16
Diagnostic Junction Port............ 8W-31-4, 15
Engine Control Module............ 8W-31-16, 17
Engine Starter Motor Relay..... 8W-31-4, 5, 6, 12
Fuel Pump Relay.................... 8W-31-4
Fuse 5........................... 8W-31-2, 3
Fuse 12......................... 8W-31-4, 15
Fuse 20.......................... 8W-31-5, 6
Fuse 21........................ 8W-31-14, 15
Fuse 28.......................... 8W-31-2, 8
Fuse 31............................ 8W-31-4
G102.......................... 8W-31-11, 13
G108.............................. 8W-31-3
G200.......................... 8W-31-14, 15
G300............................. 8W-31-15
G301............................. 8W-31-15Component Page
Generator.......................... 8W-31-2
Input Speed Sensor.................. 8W-31-13
Junction Block............. 8W-31-4, 5, 6, 14, 15
Left Rear Lamp Assembly............ 8W-31-5, 6
Line Pressure Sensor................ 8W-31-13
Output Speed Sensor.............. 8W-31-8, 13
Park/Neutral Position Switch........... 8W-31-6
Power Distribution Center......... 8W-31-2, 3, 8
Powertrain Control
Module......... 8W-31-2, 4, 5, 6, 7, 8, 9, 10, 14
Right Rear Lamp Assembly........... 8W-31-5, 6
Shifter Assembly.............. 8W-31-14, 15, 16
Throttle Position Sensor............... 8W-31-7
Transfer Case Position Sensor........ 8W-31-6, 16
Transmission Control
Module........... 8W-31-3, 4, 7, 9, 10, 11, 12,
13, 14, 16, 17, 18
Transmission Control Relay . . . 8W-31-2, 3, 8, 11, 12
Transmission Solenoid.............. 8W-31-2, 8
Transmission Solenoid Assembly........ 8W-31-18
Transmission Solenoid/TRS
Assembly.............. 8W-31-3, 5, 11, 12, 13
WJ8W-31 TRANSMISSION CONTROL SYSTEM 8W - 31 - 1

REMOVAL
REMOVAL - CAMSHAFT BEARINGS.......31
REMOVAL - CAMSHAFT................31
INSPECTION
INSPECTION - CAMSHAFT BEARINGS.....31
INSPECTION - CAMSHAFT..............31
INSTALLATION
INSTALLATION - CAMSHAFT BEARINGS . . . 32
INSTALLATION - CAMSHAFT............32
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - FITTING
CONNECTING ROD BEARINGS..........33
CRANKSHAFT
DESCRIPTION.........................35
CRANKSHAFT MAIN BEARINGS
STANDARD PROCEDURE - FITTING
CRANKSHAFT MAIN BEARINGS..........36
REMOVAL.............................39
INSPECTION..........................40
INSTALLATION.........................40
CRANKSHAFT OIL SEAL - FRONT
REMOVAL.............................41
INSTALLATION.........................41
CRANKSHAFT OIL SEAL - REAR
REMOVAL.............................42
INSTALLATION.........................42
HYDRAULIC LIFTERS
DESCRIPTION.........................43
REMOVAL.............................43
CLEANING............................43
INSPECTION..........................43
INSTALLATION.........................43
PISTON & CONNECTING ROD
DESCRIPTION.........................44
STANDARD PROCEDURE - PISTON FITTING . 44
REMOVAL.............................45
INSTALLATION.........................46
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING.............................47
VIBRATION DAMPER
REMOVAL.............................49
INSTALLATION.........................49STRUCTURAL SUPPORT
REMOVAL.............................49
INSTALLATION.........................50
LUBRICATION
DESCRIPTION.........................50
OPERATION...........................50
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE OIL
PRESSURE..........................51
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK...............................51
OIL
STANDARD PROCEDURE - ENGINE OIL
SERVICE............................53
OIL FILTER
REMOVAL.............................53
INSTALLATION.........................54
OIL PAN
DESCRIPTION.........................54
REMOVAL.............................54
INSTALLATION.........................55
ENGINE OIL PRESSURE SENSOR
DESCRIPTION.........................56
OPERATION...........................56
OIL PUMP
REMOVAL.............................56
INSTALLATION.........................57
INTAKE MANIFOLD
DESCRIPTION.........................57
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKAGE..................57
REMOVAL.............................57
INSTALLATION.........................57
EXHAUST MANIFOLD
DESCRIPTION.........................58
REMOVAL.............................58
INSTALLATION.........................58
TIMING BELT / CHAIN COVER(S)
REMOVAL.............................58
INSTALLATION.........................58
TIMING BELT/CHAIN AND SPROCKETS
REMOVAL.............................60
INSTALLATION.........................60
ENGINE - 4.0L
DESCRIPTION
The 4.0 Liter (242 CID) six-cylinder engine is an
In-line, lightweight, overhead valve engine. This
engine is designed for unleaded fuel.
The engine cylinder head has dual quench-type
combustion chambers that create turbulence and fast
burning of the air/fuel mixture. This results in better
fuel economy.
The cylinders are numbered 1 through 6 from front
to rear. The firing order is 1-5-3-6-2-4 (Fig. 1).The crankshaft rotation is clockwise, when viewed
from the front of the engine. The crankshaft rotates
within seven main bearings. The camshaft rotates
within four bearings.
The engine Build Date Code is located on a
machined surface on the right side of the cylinder
block between the No.2 and No.3 cylinders (Fig. 2).
The digits of the code identify:
²1st DigitÐThe year (8 = 1998).
²2nd & 3rd DigitsÐThe month (01 - 12).
²4th & 5th DigitsÐThe engine type/fuel system/
compression ratio (MX = A 4.0 Liter (242 CID) 8.7:1
compression ratio engine with a multi-point fuel
injection system).
9 - 2 ENGINE - 4.0LWJ

²6th & 7th DigitsÐThe day of engine build (01 -
31).(1)FOR EXAMPLE:Code * 801MX12 * identifies
a 4.0 Liter (242 CID) engine with a multi-point fuel
injection system, 8.7:1 compression ratio and built on
January 12, 1998.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING - Preformance) or (Refer to 9 - ENGINE - DIAG-
NOSIS AND TESTING - Mechanical). Refer to 14 -
FUEL SYSTEM for 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.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING)
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
²Cylinder Head Gasket Failure Diagnosis (Refer
to 9 - ENGINE/CYLINDER HEAD - DIAGNOSIS
AND TESTING)
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING)
²Lash Adjuster (Tappet) Noise Diagnosis (Refer to
9 - ENGINE/ENGINE BLOCK/HYDRAULIC LIFT-
ERS (CAM IN BLOCK) - DIAGNOSIS AND TEST-
ING)
²Engine Oil Leak Inspection (Refer to 9 -
ENGINE/LUBRICATION - DIAGNOSIS AND TEST-
ING)
Fig. 1 Engine Firing Order
Fig. 2 Build Date Code Location
1 - YEAR
2 - MONTH
3-DAY
WJENGINE - 4.0L 9 - 3
ENGINE - 4.0L (Continued)

DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
ENGINE PERFORMANCE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
ENGINE WILL NOT CRANK 1. Weak or dead battery 1. Charge/Replace Battery. (Refer to
8 - ELECTRICAL/BATTERY
SYSTEM/BATTERY - STANDARD
PROCEDURE), for correct
procedures. Check charging system.
(Refer to 8 - ELECTRICAL/
CHARGING - DIAGNOSIS AND
TESTING), for correct procedures.
2. Corroded or loose battery
connections2. Clean/tighten suspect battery/
starter connections
3. Faulty starter or related circuit(s) 3. Check starting system. (Refer to 8
- ELECTRICAL/STARTING -
DIAGNOSIS AND TESTING), for
correct diagnostics/procedures
4. Siezed accessory drive
component4. Remove accessory drive belt and
attempt to start engine. If engine
starts, repair/replace siezed
component.
5. Engine internal mechanical failure
or hydro-static lock5. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING), for
correct diagnostics/procedures
ENGINE CRANKS BUT WILL
NOT START1. No spark 1. Check for spark. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL -
SPECIFICATIONS), for correct
procedures.
2. No fuel 2. Perform fuel pressure test (Refer
to 14 - FUEL SYSTEM/FUEL
DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING), and if
necessary, inspect fuel injector(s) and
driver circuits. (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/FUEL
INJECTOR - DIAGNOSIS AND
TESTING), for correct procedures.
3. Low or no engine compression 3. Perform cylinder compression
pressure test. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
ENGINE LOSS OF POWER 1. Worn or burned distributor rotor 1. Install new distributor rotor
2. Worn camshaft position sensor
shaft2. Remove and repair camshaft
position sensor.(Refer to 8 -
ELECTRICAL/IGNITION CONTROL/
CAMSHAFT POSITION SENSOR -
REMOVAL).
9 - 4 ENGINE - 4.0LWJ
ENGINE - 4.0L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
3. Worn or incorrect gapped spark
plugs3. Clean plugs and set gap. (Refer to
8 - ELECTRICAL/IGNITION
CONTROL/SPARK PLUG -
CLEANING).
4. Dirt or water in fuel system 4. Clean system and replace fuel
filter
5. Faulty fuel pump 5. Install new fuel pump
6. Incorrect valve timing 6. Correct valve timing
7. Blown cylinder head gasket 7. Install new cylinder head gasket
8. Low compression 8. Test cylinder compression. (Refer
to 9 - ENGINE - DIAGNOSIS AND
TESTING).
9. Burned, warped, or pitted valves 9. Install/Reface valves as necessary
10. Plugged or restricted exhaust
system10. Install new parts as necessary
11. Faulty ignition coil rail 11. Test and replace, as necessary.
(Refer to 8 - ELECTRICAL/IGNITION
CONTROL/COIL RAIL - REMOVAL).
ENGINE STALLS OR ROUGH
IDLE1. Carbon build-up on throttle plate 1. Remove throttle body and
de-carbon. (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/
THROTTLE BODY - REMOVAL) for
correct procedure.
2. Engine idle speed too low 2. Check Idle Air Control circuit.
3. Worn or incorrectly gapped spark
plugs3. Replace or clean and re-gap spark
plugs. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING)
4. Faulty coil rail 4. Test and replace, if necessary.
(Refer to 8 - ELECTRICAL/IGNITION
CONTROL/COIL RAIL - REMOVAL)
5. Intake manifold vacuum leak 5. Inspect intake manifold gasket and
vacuum hoses. Replace if necessary.
(Refer to 9 - ENGINE/MANIFOLDS/
INTAKE MANIFOLD - DIAGNOSIS
AND TESTING).
ENGINE MISSES ON
ACCELERATION1. Worn or incorrectly gapped spark
plugs1. Replace spark plugs or clean and
set gap.
2. Spark plug cables defective or
crossed2. Replace spark plug cables.
3. Dirt in fuel system 3. Clean fuel system
4. Burned, warped or pitted valves 4. Install new valves
5. Faulty coil rail 5. Test and replace as necessary.
(Refer to 8 - ELECTRICAL/IGNITION
CONTROL/COIL RAIL - REMOVAL)
WJENGINE - 4.0L 9 - 5
ENGINE - 4.0L (Continued)

FORM-IN-PLACE GASKET AND SEALER
APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier then using precut gaskets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
MopartEngine RTV GEN II or ATF RTV gasket
material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All
mounting holes must be circled. For corner sealing, a
3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the
center of the gasket contact area. Uncured sealant
may be removed with a shop towel. Components
should be torqued in place while the sealant is still
wet to the touch (within 10 minutes). The usage of a
locating dowel is recommended during assembly to
prevent smearing material off the location.
MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
STANDARD PROCEDURE - REPAIR DAMAGED
OR WORN THREADS
CAUTION: Be sure that the tapped holes maintain
the original center line.
Damaged or worn threads can be repaired. Essen-
tially, this repair consists of:
²Drilling out worn or damaged threads.
²Tapping the hole with a special Heli-Coil Tap, or
equivalent.
²Installing an insert into the tapped hole to bring
the hole back to its original thread size.
STANDARD PROCEDUREÐHYDROSTATIC LOCK
CAUTION: DO NOT use the starter motor to rotate
the crankshaft. Severe damage could occur.
When an engine is suspected of hydrostatic lock
(regardless of what caused the problem), follow the
steps below.
(1) Perform the Fuel Pressure Release Procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).(2) Disconnect the negative cable(s) from the bat-
tery.
(3) Inspect air cleaner, induction system, and
intake manifold to ensure system is dry and clear of
foreign material.
(4) Place a shop towel around the spark plugs to
catch any fluid that may possibly be under pressure
in the cylinder head. Remove the spark plugs.
(5) With all spark plugs removed, rotate the crank-
shaft using a breaker bar and socket.
(6) Identify the fluid in the cylinders (coolant, fuel,
oil, etc.).
(7) Be sure all fluid has been removed from the
cylinders.
(8) Repair engine or components as necessary to
prevent this problem from occurring again.
(9) Squirt a small amount of engine oil into the
cylinders to lubricate the walls. This will prevent
damage on restart.
(10) Install new spark plugs. Tighten the spark
plugs to 41 N´m (30 ft. lbs.) torque.
(11) Drain engine oil. Remove and discard the oil
filter.
(12) Install the drain plug. Tighten the plug to 34
N´m (25 ft. lbs.) torque.
(13) Install a new oil filter.
(14) Fill engine crankcase with the specified
amount and grade of oil. (Refer to LUBRICATION &
MAINTENANCE - SPECIFICATIONS).
(15) Connect the negative cable(s) to the battery.
(16) Start the engine and check for any leaks.
STANDARD PROCEDURE - CYLINDER BORE
HONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1)
Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light scuff-
ing, scoring and scratches. Usually, a few strokes will
clean up a bore and maintain the required limits.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
9 - 10 ENGINE - 4.0LWJ
ENGINE - 4.0L (Continued)

(7) Remove the fan assembly from the water pump
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(8) Remove the fan shroud.
(9) Disconnect the transmission fluid cooler lines
(automatic transmission).
(10) Discharge the A/C system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(11) Remove the service valves and cap the com-
pressor ports.
(12) Remove the radiator or radiator/condenser (if
equipped with A/C).
(13) Disconnect the heater hoses at the engine
thermostat housing and water pump.
(14) Disconnect the accelerator cable, transmission
line pressure cable and speed control cable (if
equipped) from the throttle body.
(15) Remove cables from the bracket and secure
out of the way.
(16) Disconnect the body ground at the engine.
(17) Disconnect the following connectors and
secure their harness out of the way.
²Power steering pressure switch
²Coolant temperature sensor
²Six (6) fuel injector connectors
²Intake air temperature sensor
²Throttle position sensor
²Map sensor
²Crankshaft position sensor
²Oxygen sensor
²Camshaft position sensor
²Generator connector and B+ terminal wire
(18) Disconnect the coil rail electrical connections
and the oil pressure switch connector.
(19) Perform the fuel pressure release procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(20) Disconnect the fuel supply line at the injector
rail (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
QUICK CONNECT FITTING - STANDARD PROCE-
DURE).
(21) Remove the fuel line bracket from the intake
manifold.
(22) Remove the air cleaner assembly (Fig. 5).
(23) Disconnect the hoses from the fittings at the
steering gear.
(24) Drain the pump reservoir.
(25) Cap the fittings on the hoses and steering
gear to prevent foreign objects from entering the sys-
tem.
(26) Raise and support the vehicle.
(27) Disconnect the wires from the engine starter
motor solenoid.(28) Remove the engine starter motor (Refer to 8 -
ELECTRICAL/STARTING/STARTER MOTOR -
REMOVAL).
(29) Disconnect the oxygen sensor from the
exhaust pipe.
(30) Disconnect the exhaust pipe from the mani-
fold.
(31) Remove the exhaust pipe support.
(32) Remove the bending brace (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCT SUPPORT -
REMOVAL).
(33) Remove the engine flywheel/converter housing
access cover.
(34) Mark the converter and drive plate location.
(35) Remove the converter-to-drive plate bolts.
(36) Remove the upper engine flywheel/converter
housing bolts and loosen the bottom bolts.
(37) Remove the engine mount cushion-to-engine
compartment bracket bolts.
(38) Lower the vehicle.
(39) Attach a lifting device to the engine.
(40) Raise the engine off the front supports.
(41) Place a support or floor jack under the con-
verter (or engine flywheel) housing.
(42) Remove the remaining converter (or engine
flywheel) housing bolts.
(43) Lift the engine out of the engine compart-
ment.
Fig. 5 Air Cleaner Assembly
1 - POWER STEERING PUMP
2 - AIR CLEANER ASSEMBLY
9 - 12 ENGINE - 4.0LWJ
ENGINE - 4.0L (Continued)

INSTALLATION
CAUTION: When installing the engine into a vehicle
equipped with an automatic transmission, be care-
ful not to damage the trigger wheel on the engine
flywheel.
(1) Attach a lifting device to the engine and lower
the engine into the engine compartment. For easier
installation, it may be necessary to remove the
engine mount bracket as an aid in alignment of the
engine to the transmission.
(2) Align the transmission torque converter hous-
ing with the engine.
(3) Loosely install the converter housing lower
bolts and install the next higher bolt and nut on each
side.
(4) Tighten all 4 bolts finger tight.
(5) Install the engine mount brackets (if removed).
(6) Lower the engine and engine mount brackets
onto the engine compartment cushions. Install the
bolts and finger tighten the nuts.
(7) Remove the engine lifting device.
(8) Raise and support the vehicle.
(9) Install the remaining engine flywheel/converter
housing bolts. Tighten all bolts to 38 N´m (28 ft. lbs.)
torque.
(10) Install the converter-to-drive plate bolts.
(11) Ensure the installation reference marks are
aligned.
(12) Install the engine flywheel/converter housing
access cover.
(13) Install the exhaust pipe support and tighten
the screw.
(14) Install the engine bending brace (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCT SUPPORT -
INSTALLATION).
(15) Tighten the engine mount-to-bracket bolts.
(16) Connect the vehicle speed sensor wire connec-
tions and tighten the screws.
(17) Connect the exhaust pipe to the manifold.
(18) Install the engine starter motor (Refer to 8 -
ELECTRICAL/STARTING/STARTER MOTOR -
INSTALLATION).
(19) Connect the wires to the engine starter motor
solenoid.
(20) Lower the vehicle.
(21) Connect all the vacuum hoses and wire con-
nectors identified during engine removal.
(22) Remove protective caps from the power steer-
ing hoses.
(23) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 N´m (38 ft. lbs.)
torque.
(24) Fill the pump reservoir with fluid.(25) Inspect the fuel supply line o-ring(s) and
replace if necessary. Connect fuel supply line to injec-
tior rail and verify connection by pulling outward on
the line.
(26) Install the fuel line bracket to the intake
manifold.
(27) Connect the coil rail electrical connectors and
oil pressure switch connector.
(28) Connect the following electrical connectors:
²Power steering pressure switch
²Coolant temperature sensor
²Six (6) fuel injector connectors
²Intake air temperature sensor
²Throttle position sensor
²Map sensor
²Crankshaft position sensor
²Oxygen sensor
²Camshaft position sensor
²Generator connector and B+ terminal wire
(29) Connect all previously removed vacuum hoses.
(30) Connect the body ground strap.
(31) Install the throttle, transmission line pres-
sure, and speed control cables to their mounting
bracket and connect them to the throttle body.
(32) Connect the heater hoses at the engine ther-
mostat housing and water pump.
(33) Install the fan assembly (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - INSTALLATION).
(34) Place the fan shroud in position over the fan.
(35) Install the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - INSTALLATION).
(36) Connect the service valves to the A/C com-
pressor ports, if equipped with A/C.
(37) Charge the air conditioner system (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(38) Connect the radiator hoses and automatic
transmission fluid cooler pipes, if equipped.
(39) Install the fan shroud to the radiator or radi-
ator/condenser (if equipped with A/C).
(40) Install upper radiator support.
(41) Connect the upper radiator hose and tighten
the clamp.
(42) Connect the lower radiator hose and tighten
the clamp.
(43) Fill crankcase with engine oil. (Refer to
LUBRICATION & MAINTENANCE/FLUID CAPACI-
TIES - SPECIFICATIONS) for correct capacities.
(44) Fill the cooling system with reusable coolant
or new coolant (Refer to 7 - COOLING - STANDARD
PROCEDURE).
(45) Align the hood to the scribe marks. Install the
hood.
(46) Install the air cleaner assembly.
(47) Install the battery and connect the battery
cable.
WJENGINE - 4.0L 9 - 13
ENGINE - 4.0L (Continued)