Pin IAT sensor ISUZU TROOPER 1998 Service Repair Manual

RESULT SYMPTOM TROUBLE CAUSE CORRECTION
SERVICE INFORMATION 00 Ð 25
Reduced or no air flow through
the condenser
No bubbles in sight glass when
condenser is cooled by water
(Insufficient cooling)
After stopping air conditioning,
pressure drops approx. 196 kPa
(28 PSI) quickly
Insufficient cooling and excessive
bubbles in the sight glass
Low pressure gauge indicates
vacuum
Frost or dew on refrigerant line
before and after receiver/ drier or
expansion valve, and low pres-
sure gauge indicates vacuum
After turning off air conditioning,
high and low pressure gauge
balanced quickly
Low pressure gauge is lowered
after condenser is cooled by
water
Low pressure hose temperature
around the compressor refriger-
ant line connector is lower than
around evaporator
After turning off air conditioning,
high and low pressure gauge is
balanced quickly
Air conditioning turns off before
passenger compartment is suffi-
ciently cool·Condenser clogged or dirty
·Radiator (condenser) fan
does not operate properly
·Excessive refrigerant in
system
·Air in system
·Insufficient refrigerant in
system
·Clogged or defective expan-
sion valve
·Restriction caused by debris
or moisture in receiver/drier
·Compressor seal defective
·Poor compression due to
defective compressor gasket
·Excessive refrigerant in
system
·Unsatisfactory valve opera-
tion due to defective temper-
ature sensor of expansion
valve
·Expansion valve opens too
long
·Compressor gasket is defec-
tive
·Electronic thermostat defec-
tive·Clean
·Check cooling fan
operation
·Check sight glass.
(See ÒReading Sight
GlassÓ)
·Discharge and
recover refrigerant.
Recharge to speci-
fied amount
·Evacuate and
charge refrigerant
system
·Check sight glass.
(See ÒReading Sight
GlassÓ)
·Check for leaks
·Discharge and
recover refrigerant.
Recharge to speci-
fied amount
·Replace the expan-
sion valve
·Check system for
restriction and
replace
receiver/drier
·Replace or repair
compressor
·Discharge and
recover refrigerant
Recharge to speci-
fied amount
·Replace the expan-
sion valve
·Replace
·Check the electronic
thermostat and
replace as neces-
saryDischarge
(High) pres-
sure gauge
abnormally
high
Discharge
(High) pres-
sure gauge
abnormally
low
Suction
(Low) pres-
sure gauge
abnormally
high
* For the charging and discharging operations in the table above, refer to ÒRECOVERY, RECYCLING,
EVACUATION AND CHARGINGÓ in this section.

1B Ð 4 AIR CONDITIONING
The refrigeration cycle includes the following four
processes as the refrigerant changes repeatedly
from liquid to gas and back to liquid while
circulating.
EVAPORATION
The refrigerant is changed from a liquid to a gas
inside the evaporator. The refrigerant mist that
enters the evaporator vaporizes readily. The liquid
refrigerant removes the required quantity of heat
(latent heat of vaporization) from the air around the
evaporator core cooling fins and rapidly vaporizes.
Removing the heat cools the air, which is then
radiated from the fins and lowers the temperature
of the air inside the vehicle.
The refrigerant liquid sent from the expansion valve
and the vaporized refrigerant gas are both present
inside the evaporator and the liquid is converted to
gas.
With this change from liquid to gas, the pressure
inside the evaporator must be kept low enough for
vaporization to occur at a lower temperature.
Because of that, the vaporized refrigerant is sucked
into the compressor.
COMPRESSION
The refrigerant is compressed by the compressor
until it is easily liquefied at normal temperature.
The vaporized refrigerant in the evaporator is
sucked into the compressor. This action maintains
the refrigerant inside the evaporator at a low
pressure so that it can easily vaporize, even at low
temperatures close to 0¡C (32¡F).
Also, the refrigerant sucked into the compressor is
compressed inside the cylinder to increase the
pressure and temperature to values such that the
refrigerant can easily liquefy at normal ambient
temperatures.
CONDENSATION
The refrigerant inside the condenser is cooled by
the outside air and changes from gas to liquid.
The high temperature, high pressure gas coming
from the compressor is cooled and liquefied by the
condenser with outside air and accumulated in the
receiver/drier. The heat radiated to the outside air
by the high temperature, high pressure gas in the
compressor is called heat of condensation. This is
the total quantity of heat (heat of vaporization) the
refrigerant removes from the vehicle interior via the
evaporator and the work (calculated as the quantity
of heat) performed for compression.
EXPANSION
The expansion valve lowers the pressure of the
refrigerant liquid so that it can easily vaporize.
The process of lowering the pressure to encourage
vaporization before the liquefied refrigerant is sent
to the evaporator is called expansion. In addition,
the expansion valve controls the flow rate of the
refrigerant liquid while decreasing the pressure.
That is, the quantity of refrigerant liquid vaporized
inside the evaporator is determined by the quantity
of heat which must be removed at a prescribed
vaporization temperature. It is important that the
quantity of refrigerant be controlled to exactly the
right value.
COMPRESSOR
The compressor performs two main functions:
It compresses low-pressure and low-temperature
refrigerant vapor from the evaporator into high-
pressure and high-temperature refrigerant vapor to
the condenser. And it pumps refrigerant and
refrigerant oil through the A/C system.
6VD1/6VE1 engine on RHD model is equipped with
an invariable capacity five-vane rotary compressor
(DKV-14D Type).
The compressor sucks and compresses refrigerant
by the rotation of the vane installed to the shaft,
and always discharges a fixed amount of refrigerant
independent of the load of refrigerant.
The thermo sensor is installed to the front head of
the compressor to protect it by stopping its
operation when the refrigerant gas is insufficient or
when the temperature is abnormally high.
·OFF ....... 160 ±5¡C (320.0 ±41¡F)
·ON ........ 135 ±5¡C (275.0 ±41¡F)
Diesel Engine models and 6VD1/6VE1 engine on
LHD model are equipped with a swash plate type
compressor
Swash plate compressors have a swash (slanted)
plate mounted on the shaft. When the shaft turns,
the rotation of the swash plate is converted to
reciprocating piston motion which sucks in and
compresses the refrigerant gas.
Shaft seal (Lip type) is installed between the valve
plate and shaft & cylinder head to prevent
refrigerant gas leaks. A specified amount of
compressor oil is contained in the oil pan.
This oil is supplied to the cylinders, bearings, etc.,
by an oil pump which is connected to the swash
plate shaft.

4C±4
DRIVE SHAFT SYSTEM
Rear Axle Shaft
Rear Axle Shaft and Associated Parts
420RW014
Legend
(1) Brake Caliper
(2) Brake Disc
(3) Wheel Pin
(4) Axle Shaft Assembly
(5) Back Plate
(6) Parking Brake Assembly
(7) Bearing Holder(8) Bearing
(9) Retainer
(10) Snap Ring
(11) Bolt
(12) Nut
(13) Antilock Brake System (ABS) Speed Sensor (if
so equipped)
Removal
1. Raise the vehicle.
2. Remove tires and wheels. Refer to Wheel in Steering
section.3. Remove brake caliper. Use a wire to attach the brake
caliper to the frame. Refer to Disk Brakes in Brake
section.
4. Remove brake disc.
5. Remove ABS sensor (if so equipped).
6. Remove Parking brake assembly. Refer to Parking
Brakes in Brake section.

5A±1 BRAKE CONTROL SYSTEM
BRAKES
CONTENTS
Brake Control System 5A. . . . . . . . . . . . . . . . . . . .
Anti±lock Brake System 5B. . . . . . . . . . . . . . . . . . Power±Assisted Brake System 5C. . . . . . . . . . . .
Parking Brakes 5D. . . . . . . . . . . . . . . . . . . . . . . . .
BRAKE CONTROL SYSTEM
CONTENTS
Service Precaution 5A±2. . . . . . . . . . . . . . . . . . . . . .
General Description 5A±3. . . . . . . . . . . . . . . . . . . . .
System Components 5A±3. . . . . . . . . . . . . . . . . . .
Electronic Hydraulic Control Unit (EHCU) 5A±3.
ABS Warning Light 5A±4. . . . . . . . . . . . . . . . . . . .
Wheel Speed Sensor 5A±4. . . . . . . . . . . . . . . . . .
G-Sensor 5A±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal and Anti-lock Braking 5A±4. . . . . . . . . . .
Brake Pedal Travel 5A±4. . . . . . . . . . . . . . . . . . . .
Acronyms and Abbreviations 5A±4. . . . . . . . . . . .
General Diagnosis 5A±5. . . . . . . . . . . . . . . . . . . . . . .
General Information 5A±5. . . . . . . . . . . . . . . . . . . .
ABS Service Precautions 5A±5. . . . . . . . . . . . . . .
Computer System Service Precautions 5A±5. . .
General Service Precautions 5A±5. . . . . . . . . . . .
Note on Intermittents 5A±5. . . . . . . . . . . . . . . . . . .
Test Driving ABS Complaint Vehicles 5A±6. . . . .
ªABSº Warning Light 5A±6. . . . . . . . . . . . . . . . . . .
Normal Operation 5A±6. . . . . . . . . . . . . . . . . . . . .
Basic Diagnostic Flow Chart 5A±6. . . . . . . . . . . .
Basic Inspection Procedure 5A±7. . . . . . . . . . . . .
Tech 2 Scan Tool 5A±8. . . . . . . . . . . . . . . . . . . . . .
Getting Started 5A±9. . . . . . . . . . . . . . . . . . . . . . . .
Operating Procedure 5A±10. . . . . . . . . . . . . . . . . . .
Data List 5A±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EHCU Connector Pin-out Checks 5A±12. . . . . . . .
Circuit Diagram (LHD model / 6VD1 and
4JG2) 5A±13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram (LHD model / 4JG2) 5A±14. . . . .
Circuit Diagram (LHD model / 4JG2) 5A±15. . . . .
Circuit Diagram (LHD model / 6VD1) 5A±16. . . . .
Circuit Diagram (LHD model / 6VD1) 5A±17. . . . .
Connector List (LHD model) 5A±18. . . . . . . . . . . .
Part Location (LHD model) 5A±20. . . . . . . . . . . . . .
Circuit Diagram (RHD model / 6VD1 and
4JG2) 5A±21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Diagram (RHD model / 4JG2) 5A±22. . . . .
Circuit Diagram (RHD model / 4JG2) 5A±23. . . . .
Circuit Diagram (RHD model / 6VD1) 5A±24. . . . .
Circuit Diagram (RHD model / 6VD1) 5A±25. . . . .
Circuit Diagram (RHD model / 6VE1 and
4JX1) 5A±26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit Diagram (RHD model / 4JX1) 5A±27. . . . .
Circuit Diagram (RHD model / 4JX1) 5A±28. . . . .
Circuit Diagram (RHD model / 6VE1) 5A±29. . . . .
Circuit Diagram (RHD model / 6VE1) 5A±30. . . . .
Connector List (RHD model) 5A±31. . . . . . . . . . . .
Part Location (RHD model) 5A±34. . . . . . . . . . . . .
Symptom Diagnosis 5A±35. . . . . . . . . . . . . . . . . . . . .
Chart A±1 ABS Works Frequently But
Vehicle Does Not Decelerate 5A±35. . . . . . . . . . .
Chart TA-1 ABS Works Frequently But
Vehicle Does Not Decelerate (Use
TECH 2) 5A±36. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart A-2 Uneven Braking Occurs While
ABS Works 5A±36. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart A-3, TA-3 The Wheels Are Locked 5A±36.
Chart A-4 Brake Pedal Feed Is Abnormal 5A±37.
Chart A-5, TA-5 Braking Sound (From
EHCU) Is Heard While Not Braking 5A±38. . . . . .
Diagnostic Trouble Codes 5A±39. . . . . . . . . . . . . . . .
Diagnosis By ªABSº Warning Light
Illumination Pattern 5A±40. . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Codes (DTCs) 5A±40. . . . . . .
Chart B-1 With the key in the ON position
(Before starting the engine). Warning light
(W/L) is not activated. 5A±43. . . . . . . . . . . . . . . . .
Chart B-2 EHCU Abnormality (DTC 14) 5A±43. . .
Chart B-3 Power Voltage Drop (DTC 15) 5A±44. .
Chart B-4 CLASS-2 Communication Line
Abnormality (DTC 16) 5A±44. . . . . . . . . . . . . . . . .
Chart B-5 G-Sensor Circuit (DTC 21) 5A±45. . . . .
Chart B-6 Abnormal Transmission Input
(DTC 23) 5A±46. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chart B-7 Transfer Monitor (DTC 24) 5A±47. . . . .
Chart B-8 EHCU Pump Motor And Motor
Relay Circuit (DTC 32) 5A±47. . . . . . . . . . . . . . . . .
Chart B-9 EHCU Pump Valve And Valve
Relay Circuit (DTC 35) 5A±47. . . . . . . . . . . . . . . . .
Chart B-10 FL Isolation Solenoid Valve
Abnormality (DTC 41) 5A±48. . . . . . . . . . . . . . . . .
Chart B-11 FL Dump Solenoid Valve
Abnormality (DTC 42) 5A±48. . . . . . . . . . . . . . . . .
Chart B-12 FR Isolation Solenoid Valve
Abnormality (DTC 43) 5A±48. . . . . . . . . . . . . . . . .
Chart B-13 FR Dump Solenoid Valve
Abnormality (DTC 44) 5A±49. . . . . . . . . . . . . . . . .
Chart B-14 Rear Isolation Solenoid Valve
Abnormality (DTC 45) 5A±49. . . . . . . . . . . . . . . . .
Chart B-15 Rear Dump Solenoid Valve
Abnormality (DTC 46) 5A±49. . . . . . . . . . . . . . . . .

5A±4
BRAKE CONTROL SYSTEM
normal braking when a malfunction has occurred in the
ABS.
The EHCU has a self-diagnosing function which can
indicate faulty circuits during diagnosis.
The EHCU is mounted on the engine compartment front
right side. It consists of a Motor, Plunger Pump, Solenoid
Valves and Check Valve.
On the outside, the relay box containing a motor relay and
a valve relay is installed.
Solenoid Valves: Reduces or holds the caliper fluid
pressure for each front disc brake or both rear disc brakes
according to the signal sent from the EHCU.
Reservoir: Temporarily holds the brake fluid that returns
from the front and rear disc brake caliper so that pressure
of front disc brake caliper can be reduced smoothly.
Plunger Pump: Feeds the brake fluid held in the reservoir
to the master cylinder.
Motor: Drives the pump according to the signal from
EHCU.
Check Valve: Controls the brake fluid flow.
ABS Warning Light
821RW033Vehicles equipped with the Anti-lock Brake System have
an amber ªABSº warning light in the instrument panel.
The ªABSº warning light will illuminate if a malfunction in
the Anti-lock Brake System is detected by the Electronic
Hydraulic Control Unit (EHCU). In case of an electronic
malfunction, the EHCU will turn ªONº the ªABSº warning
light and disable the Anti-lock braking function.
The ªABSº light will turn ªONº for approximately three
seconds after the ignition switch is to the ªONº position.
If the ªABSº light stays ªONº after the ignition switch is the
ªONº position, or comes ªONº and stays ªONº while
driving, the Anti-lock Brake System should be inspected
for a malfunction according to the diagnosis procedure.
Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is attached
to the knuckle on the front wheels and to the axle shaft
bearing holder on the rear wheels.
The rotor is press-fit in the axle shaft.The flux generated from electrodes magnetized by a
magnet in the sensor varies due to rotation of the rotor,
and the electromagnetic induction generates alternating
voltage in the coil. This voltage draws a ªsine curveº with
the frequency proportional to rotor speed and it allows
detection of wheel speed.
G-Sensor
The G-sensor installed inside the center console detects
the vehicle deceleration speed and sends a signal to the
EHCU. In 4WD operation, all four wheels may be
decelerated in almost the same phase, since all wheels
are connected mechanically.
This tendency is noticeable particularly on roads with low
friction coefficient, and the ABS control is adversely
affected.
The G-sensor judges whether the friction coefficient of
road surface is low or high, and changes the EHCU's
operating system to ensure ABS control.
Normal and Anti-lock Braking
Under normal driving conditions, the Anti-lock Brake
System functions the same as a standard power assisted
brake system. However, with the detection of wheel
lock-up, a slight bump or kick-back will be felt in the brake
pedal. This pedal ªbumpº will be followed by a series of
short pedal pulsations which occurs in rapid succession.
The brake pedal pulsation will continue until there is no
longer a need for the anti-lock function or until the vehicle
is stopped. A slight ticking or popping noise may be heard
during brake applications when the Anti-lock features is
being used.
When the Anti-lock feature is being used, the brake pedal
may rise even as the brakes are being applied. This is
also normal. Maintaining a constant force on the pedal
will provide the shortest stopping distance.
Brake Pedal Travel
Vehicles equipped with the Anti-lock Brake System may
be stopped by applying normal force to the brake pedal.
Although there is no need to push the pedal beyond the
point where it stops or holds the vehicle, by applying more
force the pedal will continue to travel toward the floor.
This extra brake pedal travel is normal.
Acronyms and Abbreviations
Several acronyms and abbreviations are commonly used
throughout this section:
ABS
Anti-lock Brake System
CKT
Circuit
DLC
Data Link Connector
EHCU
Electronic Hydraulic Control Unit
FL
Front Left

5B±1 ANTI±LOCK BRAKE SYSTEM
BRAKES
ANTI-LOCK BRAKE SYSTEM
CONTENTS
Service Precaution 5B±1. . . . . . . . . . . . . . . . . . . . . .
Electronic Hydraulic Control Unit 5B±2. . . . . . . . . .
Electronic Hydraulic Control Unit and
Associated Parts 5B±2. . . . . . . . . . . . . . . . . . . . . .
Removal 5B±2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5B±2. . . . . . . . . . . . . . . . . . . . . . . . . . . .
G-Sensor 5B±3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 5B±3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5B±3. . . . . . . . . . . . . . . . . .
Installation 5B±3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Wheel Speed Sensor 5B±4. . . . . . . . . . . . . . . Front Wheel Speed Sensor and
Associated Parts 5B±4. . . . . . . . . . . . . . . . . . . . . .
Removal 5B±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5B±5. . . . . . . . . . . . . . . . . .
Installation 5B±5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Wheel Speed Sensor 5B±6. . . . . . . . . . . . . . .
Rear Wheel Speed Sensor and
Associated Parts 5B±6. . . . . . . . . . . . . . . . . . . . . .
Removal 5B±6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 5B±6. . . . . . . . . . . . . . . . . .
Installation 5B±6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution
WARNING: I F S O E Q U IPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM(SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.CAUTION: Re place all components included in
repair kits used to service this system. Lubricate
rubber parts with clean, fresh brake fluid to ease
assembly. Do not use shop air with in±line
lubricators on brake parts, as damage to rubber
components may result. If any hydraulic component
is removed or brake line disconnected, it may be
necessary to bleed part or all of the brake system.
NOTE: The use of rubber hoses or parts other than those
furnished specifically for the Anti±lock Brake System may
lead to functional problems requiring major overhaul.

5B±6ANTI±LOCK BRAKE SYSTEM
Rear Wheel Speed Sensor
Rear Wheel Speed Sensor and Associated Parts
350RW008
Legend
(1) Speed Sensor Connector
(2) Sensor Cable Fixing Bolt(3) Clip (11 pieces)
(4) Speed Sensor
(5) Sensor Fixing Bolt
Removal
1. Remove speed sensor connector.
2. Remove clip.
3. Remove sensor cable fixing bolt.
4. Remove sensor fixing bolt.
5. Remove speed sensor.
350RS035
Inspection and Repair
1. Check the speed sensor pole piece for presence of
foreign materials; remove any dirt, etc.2. Check the pole piece for damage, and replace the
speed sensor if necessary.
3. Check the speed sensor cable for a short or an open,
and replace with a new one if necessary. To check for
cable short or open, bend or stretch the cable while
checking for continuity.
4. Check the sensor ring for damage including tooth
chipping. If damaged replace the axle shaft assembly.
Refer to Front Hub and Disc in Drive Shaft System
section.
Installation
1. Install the speed sensor and take care not to hit the
speed sensor pole piece during installation.
2. Install the sensor fixing bolt and tighten it to the
specified torque.
Torque : 18 N´m (1.8kg´m/13 lb ft)
3. Install the sensor cable fixing bolt and tighten it to the
specified torque.
Torque : 24 N´m (2.4kg´m/18 lb ft)
NOTE: Confirm that the cable is not twisted when
connecting the speed sensor cable.
4. Install clip.
5. Install speed sensor connector.

6A±11
ENGINE MECHANICAL
Condition CorrectionPossible cause
Engine overheatingLevel of Engine Coolant too lowReplenish
Fan clutch defectiveReplace
Incorrect fan installedReplace
Thermostat defectiveReplace
Engine Coolant pump defectiveCorrect or replace
Radiator cloggedClean or replace
Radiator filler cap defectiveReplace
Level of oil in engine crankcase too
low or wrong engine oilChange or replenish
Resistance in exhaust system
increasedClean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrectReplace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shortedCorrect or replace
Cylinder head gasket damagedReplace
Engine overcoolingThermostat defectiveReplace (Use a thermostat set to
open at 82
C (180
F))
Engine lacks compressionÐÐÐÐRefer to Hard Start
OthersTire inflation pressure abnormalAdjust to recommended pressures
Brake dragAdjust
Clutch slippingAdjust or replace
Level of oil in engine crankcase too
highCorrect level of engine oil
Exhaust Gas Recirculation Valve
defectiveReplace
Engine Noisy
Abnormal engine noise often consists of various noises
originating in rotating parts, sliding parts and othermoving parts of the engine. It is, therefore, advisable to
locate the source of noise systematically.
Condition
Possible causeCorrection
Noise from crank journals or from
crank bearings
(Faulty crank journals and crankOil clearance increased due to worn
crank journals or crank bearingsReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
yj
bearings usually make dull noise that
becomes more evident when
accelerating)Crankshaft out of roundReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
Crank bearing seizedCrank bearing seized. Replace crank
bearings and crankshaft or regrind
crankshaft and install the undersize
bearing
Troubleshooting Procedure
Short out each spark plug in sequence using insulated
spark plug wire removers. Locate cylinder with defectivebearing by listening for abnormal noise that stops when
spark plug is shorted out.

6A±48
ENGINE MECHANICAL
Engine Assembly
Removal
035RW027
1. Disconnect battery ground and positive cable.
2. Remove battery.
3. Make alignment mark on the engine hood and hinges
before removal in order to return the hood to original
position exactly.
4. Remove engine hood.
5. Drain radiator coolant.
6. Disconnect accelerator cable and automatic cruise
control cable from throttle valve on common
chamber.
7. Disconnect air duct with air cleaner cover.
8. Remove air cleaner assembly.
9. Disconnect canister vacuum hose.
10. Disconnect vacuum booster hose.
11. Disconnect three engine harness connectors.
12. Disconnect harness connector to transmission (left
front side of engine compartment), disconnect shift
on the fly harness connector from front side of front
axle and remove transmission harness bracket from
engine left side.
13. Disconnect ground cable between engine and frame.
14. Disconnect bonding cable connector on the back of
right dash panel.
15. Disconnect bonding cable terminal on the left bank.
16. Disconnect starter harness connector from starter.
17. Disconnect generator harness connector from
generator.
18. Disconnect coolant reserve tank hose from radiator.
19. Remove radiator upper and lower hoses.
20. Remove upper fan shroud.
21. Remove cooling fan assembly four fixing nuts, then
the cooling fan assembly.
22. Move drive belt tensioner to loose side using wrench
then remove drive belt.23. Remove power steering pump fixing bolts, then
power steering pump. Place the power steering pump
along with piping on the body side.
24. Remove air conditioning compressor fixing bolts from
bracket and place the compressor along with piping
on the body side.
25. Remove O
2 sensor harness connectors from exhaust
front pipe.
26. Remove three exhaust pipe fixing nuts from each
bank.
27. Remove two exhaust pipe fixing nuts from each
exhaust pipe, then move exhaust pipe to rear side of
vehicle.
28. Remove flywheel dust covers.
29. Disconnect two heater hoses from engine.
30. Disconnect fuel hoses from right side of transmission.
CAUTION: Plug fuel pipes on engine side and fuel
hoses from fuel tank.
31. Remove transmission assembly. Refer to
Transmission section in this manual.
32. Support the engine by engine hoist.
33. Remove two left side engine mount fixing bolts from
engine mount on chassis side.
34. Remove two right side engine mount fixing bolts from
engine mount on chassis side.
35. Remove engine assembly.
Installation
CAUTION: W h e n assembling the engine and
transmission, confirm that dowels have been
mounted in the specified positions at the engine
side. Take care that dowel positions are different
between the manual transmission and the automatic
transmission.

6C±3
ENGINE FUEL

Adhere to all Notices and Cautions.
All gasoline engines are designed to use only unleaded
gasoline. Unleaded gasoline must be used for proper
emission control system operation.
Its use will also minimize spark plug fouling and extend
engine oil life. Using leaded gasoline can damage the
emission control system and could result in loss of
emission warranty coverage.
All cars are equipped with an Evaporative Emission
Control System. The purpose of the system is to minimize
the escape of fuel vapors to the atmosphere.
Fuel Metering
The Engine Control Module (ECM) is in complete control
of this fuel delivery system during normal driving
conditions.
The intake manifold function, like that of a diesel, is used
only to let air into the engine. The fuel is injected by
separate injectors that are mounted over the intake
manifold.
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes, which the MAP
sensor converts to a voltage output.
This sensor generates the voltage to change
corresponding to the flow of the air drawn into the engine.
The changing voltage is transformed into an electric
signal and provided to the ECM.
With receipt of the signals sent from the MAP sensor,
Intake Air Temperature sensor and others, the ECM
determines an appropriate fuel injection pulse width
feeding such information to the fuel injector valves to
effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection
system where the injectors turn on at every crankshaft
revolution. The ECM controls the injector on time so that
the correct amount of fuel is metered depending on
driving conditions.
Two interchangeable ªOº rings are used on the injector
that must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold
and supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the
engine is running. This removes air and vapors from the
fuel as well as keeping the fuel cool during hot weather
operation.
The fuel pressure control valve that is mounted on the fuel
rail maintains a pressure differential across the injectors
under all operating conditions. It is accomplished by
controlling the amount of fuel that is recirculated back to
the fuel tank based on engine demand.
See Section ªDriveability and Emissionº for more
information and diagnosis.