
FUEL INJECTION
TABLE OF CONTENTS
page page
FUEL INJECTION
OPERATION.............................16
SPECIFICATIONS........................21
SPECIAL TOOLS.........................22
ACCELERATOR PEDAL
REMOVAL..............................23
INSTALLATION...........................23
CRANKSHAFT POSITION SENSOR
DESCRIPTION...........................23
OPERATION.............................23
REMOVAL..............................23
INSTALLATION...........................24
ENGINE SPEED SENSOR
DESCRIPTION...........................24
OPERATION.............................24
FUEL INJECTOR
DESCRIPTION...........................25
OPERATION.............................25
REMOVAL..............................25
INSTALLATION...........................26
FUEL PUMP RELAY
DESCRIPTION...........................27
OPERATION.............................27
IDLE AIR CONTROL MOTOR
DESCRIPTION...........................27
OPERATION.............................27
REMOVAL..............................28INSTALLATION...........................28
INLET AIR TEMPERATURE SENSOR
DESCRIPTION...........................28
OPERATION.............................28
MAP SENSOR
DESCRIPTION...........................29
OPERATION.............................29
REMOVAL..............................30
INSTALLATION...........................30
O2 SENSOR
DESCRIPTION...........................30
OPERATION.............................31
REMOVAL..............................32
INSTALLATION...........................33
THROTTLE BODY
DESCRIPTION...........................33
OPERATION.............................34
REMOVAL..............................34
INSTALLATION...........................34
THROTTLE CONTROL CABLE
REMOVAL..............................34
INSTALLATION...........................34
THROTTLE POSITION SENSOR
DESCRIPTION...........................34
OPERATION.............................35
REMOVAL..............................35
INSTALLATION...........................35
FUEL INJECTION
OPERATION - INJECTION SYSTEM
All engines used in this section have a sequential
Multi-Port Electronic Fuel Injection system. The MPI
system is computer regulated and provides precise
air/fuel ratios for all driving conditions. The Power-
train Control Module (PCM) operates the fuel injec-
tion system.
The PCM regulates:
²Ignition timing
²Air/fuel ratio
²Emission control devices
²Cooling fan
²Charging system
²Idle speed
²Vehicle speed control
Various sensors provide the inputs necessary for
the PCM to correctly operate these systems. In addi-tion to the sensors, various switches also provide
inputs to the PCM.
The PCM can adapt its programming to meet
changing operating conditions.
Fuel is injected into the intake port above the
intake valve in precise metered amounts through
electrically operated injectors. The PCM fires the
injectors in a specific sequence. Under most operat-
ing conditions, the PCM maintains an air fuel ratio
of 14.7 parts air to 1 part fuel by constantly adjust-
ing injector pulse width. Injector pulse width is the
length of time the injector is open.
The PCM adjusts injector pulse width by opening
and closing the ground path to the injector. Engine
RPM (speed) and manifold absolute pressure (air
density) are the primary inputs that determine injec-
tor pulse width.
OPERATION - MODES OF OPERATION
As input signals to the PCM change, the PCM
adjusts its response to output devices. For example,
14 - 16 FUEL INJECTIONRS

FUEL TRANSFER PUMP
DESCRIPTION
The fuel transfer pump (fuel lift pump) is located
under the vehicle in front of the rear axle assembly
(Fig. 5). The 12±volt electric vane-type pump is oper-
ated and controlled by the Engine Control Module
(ECM) .
OPERATION
The purpose of the fuel transfer pump is to supply
(transfer) a low-pressure fuel source:fromthe fuel
tank,throughthe fuel filter/water separator andto
the fuel injection pump. Here, the low-pressure is
raised to a high-pressure by the fuel injection pump
for operation of the high-pressure fuel injectors.The fuel transfer pump is controlled by the Engine
Control Module(ECM). The ECM turns the fuel
transfer pump on for 30 seconds when the ignition
ket is turned ªONº.
With the ignition ªONº and fuel tranfer pump run-
ning, the low-pressure fuel pressure should be 13-17 psi.
FUEL INJECTION PUMP
DESCRIPTION
A radial-piston pump is used as the high pressure
pump for fuel pressure generation (Fig. 6).
REMOVAL
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL)
(3) Remove air cleaner housing assembly.
(4) Remove power steering belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(5) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(6) Support engine and remove right engine mount
assembly.
(7) Remove outer timing belt cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(8) Using special tool VM.1055, remove injection
pump sprocket retaining nut (Fig. 7).
Fig. 5 FUEL TRANSFER(LIFT) PUMP LOCATION
1 - LIFT PUMP RETAINING BOLTS
2 - LIFT PUMP
3 - FUEL FILTER/WATER SEPARATOR HOUSING
4 - FUEL HEATER
5 - CHECK BALL
6 - O-RING
7 - FLOW DIVERTER
8 - FUEL FILTER
9 - O-RING
10 - FUEL FILTER BOWL ASSEMBLY
Fig. 6 FUEL INJECTION PUMP
1 - FUEL INJECTION PUMP
2 - INJECTION PUMP PRESSURE SOLENOID
14a - 6 FUEL DELIVERYRG

(12) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(13) Install power steering belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(14) Install air cleaner housing assembly.
(15) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION).
(16) Connect negative battery cable.
WATER IN FUEL SENSOR
DESCRIPTION
The WIF sensor is located in the bowl assembly of
the fuel filter/water separator.
OPERATION
The sensor sends an input to the Engine Control
Module (ECM) when it senses water in the fuel filter/
water separator. As the water level in the filter/sep-
arator increases, the resistance across the WIF
sensor decreases. This decrease in resistance is sent
as a signal to the ECM and compared to a high
water standard value. Once the value reaches 30 to
40 kilohms, the ECM will activate the water-in-fuel
warning lamp through CCD bus circuits. This all
takes place when the ignition key is initially put in
the ON position. The ECM continues to monitor the
input at the end of the intake manifold air heater
post-heat cycle.
RGFUEL DELIVERY14a-9
FUEL INJECTION PUMP (Continued)

INSTALLATION - PUMP (2.4L ENGINE)
(1) Install power steering pump back in vehicle
using the reverse order of its removal through the
exhaust tunnel are of the vehicle.
(2) Install the power steering pump on its cast
mounting bracket (Fig. 7), then install the nut and
bolt attaching the front bracket to the cast bracket
(Fig. 8).Do not fully tighten at this time..
(3) Install the rear nut (Fig. 7).
(4) Install the power steering pump drive belt on
pulley and adjust (Refer to 7 - COOLING/ACCES-
SORY DRIVE/DRIVE BELTS - INSTALLATION).(5) Tighten the two adjustment slot bolts and the
one pivot bolt to 54 N´m (40 ft.lbs.) torque.
(6) Install the accessory drive splash shield.
NOTE: Before installing power steering fluid pres-
sure hose on power steering pump, inspect the
O-ring on the pressure hose for damage and
replace if necessary.
(7) Install the power steering fluid pressure line
onto the output fitting of the power steering pump
(Fig. 6). Tighten the pressure line to pump fitting
tube nut to a torque of 31 N´m (275 in. lbs.).
(8) Install the power steering fluid low pressure
return hose on the power steering pump low pressure
fitting (Fig. 6).Be sure hose clamps are properly
reinstalled.
(9) Install the power steering fluid supply hose on
the power steering pump fluid fitting.Be sure hose
is clear of accessory drive belts all hose clamps
are properly reinstalled.
(10) When used, properly position the protective
heat sleeve on the power steering return hose. Tie
strap the heat sleeve to the power steering hose to
keep in it's proper position.
(11) Install the exhaust system (Fig. 4). Install all
exhaust system isolators/hangers on the exhaust sys-
tem brackets, then the four bolts and flag nuts (Fig.
3).
(12) Connect the oxygen sensor wiring harness to
the vehicle wiring harness.
(13) Lower vehicle.
(14) Connect the negative battery cable on the
negative battery post.
(15) Perform the POWER STEERING PUMP INI-
TIAL OPERATION procedure to properly fill and
bleed the power steering system. (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE)
(16) Inspect for leaks.
INSTALLATION - PUMP (3.3L/3.8L ENGINE)
(1) Install power steering pump back in vehicle
using the reverse order of its removal through the
engine compartment of the vehicle.
(2) Install the power steering pump on its mount-
ing bracket.
(3) Install the 3 front and 1 rear power steering
pump mounting bolts (Fig. 9). Remember to place
spacer between pump and rear mounting bracket
when installing rear mounting bolt. Tighten the
power steering pump mounting bolts to a torque of
54 N´m (40 ft. lbs.).
NOTE: Before installing power steering pressure
hose on power steering pump, inspect the O-ring
on the power steering pressure hose for damage
and replace if required.
Fig. 13 Pulley Installation
1 - POWER STEERING PUMP DRIVE PULLEY
2 - SPECIAL TOOL
C-4063±A
Fig. 14 Pulley To Pump Shaft Location
1 - PULLEY
2 - PUMP BODY
3 - PUMP SHAFT
4 - HUB
RSPUMP19-29
PUMP (Continued)

(4) Install the power steering fluid pressure line
into the pressure output fitting of the power steering
pump (Fig. 11). Tighten the pressure line to pump fit-
ting tube nut to a torque of 31 N´m (275 in. lbs.).
(5) Install the power steering fluid low-pressure
return hose on the power steering pump low pressure
fitting (Fig. 11).Be sure hose clamps are prop-
erly reinstalled.
(6) Raise the vehicle.
(7) Install the routing clip on the engine for the
pressure hose (Fig. 10).
(8) Tighten the pump thru-bolt (Fig. 9). Tighten to
54 N´m (40 ft. lbs.) torque.
(9) Install the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(10) Install the drive belt splash shield.
(11) Lower the vehicle.
(12) Install the wiper module (unit)(Refer to 8 -
ELECTRICAL/WIPERS/WASHERS/WIPER MOD-
ULE - INSTALLATION).
(13) Connect the negative battery cable on the
negative battery post.
(14) Fill and bleed the power steering system
using the Power Steering Pump Initial Operation
Procedure (Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE).
(15) Inspect for leaks.
SPECIAL TOOLS
POWER STEERING PUMP
FLUID
STANDARD PROCEDURE - POWER STEERING
FLUID LEVEL CHECKING
WARNING: FLUID LEVEL SHOULD BE CHECKED
WITH THE ENGINE OFF TO PREVENT INJURY
FROM MOVING PARTS.
The fluid level can be read on the exterior of the
power steering fluid reservoir. The fluid level should
be within the ªFILL RANGEº when the fluid is at
normal ambient temperature, approximately 21ÉC to
27ÉC (70ÉF to 80ÉF) (Fig. 15).
Before removing the power steering filler cap, wipe
the reservoir filler cap free of dirt and debris. Do not
overfill the power steering system. Use onlyMopart
Power Steering Fluid (MS-5931)or quivalent.
FLUID COOLER
DESCRIPTION
All models of this vehicle are equipped with a
cooler for the power steering system fluid. The power
steering fluid cooler is located on the front suspen-
sion cradle crossmember reinforcement (Fig. 16).
There are two different size coolers offered depending
on options. There is a standard 6-inch and an 8-inch
for vehicles equipped with the heavy duty cooling
package.
OPERATION
The purpose of the power steering fluid cooler is to
keep the temperature of the power steering system
fluid from rising to a level that would affect the per-
formance of the power steering system.
Installer C-4063B
Puller C-4333
Fig. 15 POWER STEERING FLUID RESERVOIR
19 - 30 PUMPRS
PUMP (Continued)

PUMP
TABLE OF CONTENTS
page page
PUMP
DESCRIPTION............................6
REMOVAL...............................6
INSTALLATION............................6RESERVOIR
DESCRIPTION............................7
REMOVAL...............................7
INSTALLATION............................7
PUMP
DESCRIPTION - PUMP (2.5L DIESEL)
Hydraulic pressure for the operation of the power
steering gear is provided by a belt driven power
steering pump. The power steering pump is mounted
front lower right corner of the engine (Fig. 2).
The pump has a supply fitting for fluid coming
from the reservoir and a pressure port for exiting
fluid that is headed for the steering gear.
REMOVAL - PUMP (2.5L DIESEL)
(1) Remove the negative (-) battery cable from the
battery and isolate cable.
(2) Remove the fill cap from the power steering
fluid reservoir.
(3) Using a siphon pump, remove as much power
steering fluid as possible from the fluid reservoir.
(4) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(5) Remove the splash shields from below the
engine compartment.
(6) Remove the accessory drive belt from the power
steering pump pulley. (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - REMOVAL)
(7) Disconnect the fluid supply hose from the
pump (Fig. 1).
(8) Disconnect the pressure hose from the pump
(Fig. 1).
(9) Remove the bolt fastening the stamped bracket
on the rear of the pump to the cast bracket (Fig. 2).
(10) Remove the three front mounting bolts
through the pulley.
(11) Remove the pump from the cast bracket and
vehicle.
INSTALLATION - PUMP (2.5L DIESEL)
(1) Install the power steering pump on its cast
mounting bracket.
(2) Install the three front power steering pump
mounting bolts. Tighten the mounting bolts to a
torque of 54 N´m (40 ft. lbs.).(3) Install the rear mounting bolt fastening the
stamped bracket to the cast bracket (Fig. 2). Tighten
the mounting bolt to a torque of 54 N´m (40 ft. lbs.).
NOTE: Before installing power steering pressure
hose on power steering pump, inspect the O-ring
on the power steering pressure hose for damage
and replace if required.
(4) Install the power steering fluid pressure hose
fitting into the pressure port of the power steering
pump (Fig. 1). Tighten the pressure line to pump fit-
ting tube nut to a torque of 31 N´m (275 in. lbs.).
(5) Install the power steering fluid supply hose on
the power steering pump supply fitting (Fig. 1).Be
sure hose clamp is properly reinstalled.
(6) Install the accessary drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
Fig. 1 POWER STEERING PUMP - 2.5L DIESEL
1 - PRESSURE HOSE
2 - HOSE CLAMP
3 - SUPPLY HOSE
4 - POWER STEERING PUMP
19a - 6 PUMPRG

REMOVAL.............................118
INSTALLATION..........................118
THROTTLE VALVE CABLE
REMOVAL.............................118
INSTALLATION..........................118
ADJUSTMENTS.........................120
TORQUE CONVERTER
DESCRIPTION..........................120
OPERATION............................123
REMOVAL.............................125
INSTALLATION..........................125
TRANSFER SYSTEM - OUTPUT SHAFT/GEAR/
BEARING
REMOVAL.............................126
INSTALLATION..........................129
ADJUSTMENTS.........................132TRANSFER SYSTEM - TRANSFER SHAFT/
GEAR/BEARING
REMOVAL.............................134
INSTALLATION..........................137
ADJUSTMENTS.........................142
VALVE BODY
REMOVAL.............................142
DISASSEMBLY..........................145
CLEANING.............................151
INSPECTION...........................152
ASSEMBLY............................152
INSTALLATION..........................155
ADJUSTMENTS.........................157
VEHICLE SPEED SENSOR/PINION GEAR
REMOVAL.............................157
INSTALLATION..........................157
AUTOMATIC - 31TH
DESCRIPTION
This transaxle combines torque converter, three
speed transmission, final drive gearing, and differen-
tial into a front wheel drive system.
Within this transaxle, there are three primary
areas:
(1) Main center line plus valve body.
(2) Transfer shaft center line (includes governor
and parking sprag).
(3) Differential center line.
Center distances between the main rotating parts
in these three areas are held precise to maintain a
low noise level.
The torque converter, transaxle area, and differen-
tial are housed in an integral aluminum die casting.
The differential oil sump is common with the
transaxle sump. Separate filling of the differen-
tial is NOT necessary.
The torque converter is attached to the crankshaft
through a flexible driving plate. Cooling of the con-
verter is accomplished by circulating the transaxle
fluid through a remote cooler. There are two types of
coolers used. An oil-to-water type cooler located in
the radiator side tank and/or an oil-to-air heat
exchanger. The torque converter assembly is a sealed
unit that cannot be disassembled.
The transaxle fluid is filtered by an internal filter
attached to the lower side of the valve body assembly.Engine torque is transmitted to the torque con-
verter and then through the input shaft to multiple-
disc clutches in the transaxle. The power flow
depends on the application of the clutches and bands.
Refer to Elements in Use Chart in Diagnosis and
Tests section.
The transaxle consists of:
²Two multiple-disc clutches
²An overrunning clutch
²Two servos
²A hydraulic accumulator
²Two bands
²Two planetary gear sets
This provides three forward ratios and a reverse
ratio. The common sun gear of the planetary gear
sets is connected to the front clutch by a driving
shell. The driving shell is splined to the sun gear and
front clutch retainer. The hydraulic system consists
of an oil pump and a single valve body which con-
tains all of the valves except the governor valves.
The transaxle sump and differential sump are both
vented through the dipstick. Output torque from the
main center line is delivered through helical gears to
the transfer shaft. This gear set is a factor in the
transaxle final drive (axle) ratio. The shaft also car-
ries the governor and parking sprag. An integral heli-
cal gear on the transfer shaft drives the differential
ring gear.
21 - 22 AUTOMATIC - 31THRS

CONDITION POSSIBLE CAUSES CORRECTION
STUCK IN LOW GEAR
(WILL NOT UPSHIFT)1. Throttle Linkage Misadjusted/Stuck. 1. Adjust linkage and repair linkage if
worn or damaged. Check for binding
cable.
2. Gearshift Linkage Misadjusted. 2. Adjust linkage and repair linkage if
worn or damaged.
3. Governor/Valve Body, Governor Valve
Stuck Closed; Loose Output Shaft
Support or Governor Housing Bolts,
Leaking Seal Rings or Valve Body
Problem (i.e., Stuck 1- 2 Shift Valve/Gov.
Plug).3. Check line and governor pressures to
determine cause. Correct as required.
4. Front Band Out of Adjustment . 4. Adjust Band.
5. Clutch or Servo Malfunction. 5. Air pressure check operation of
clutches and bands. Repair faulty
component.
CREEPS IN NEUTRAL 1. Gearshift Linkage Misadjusted. 1. Adjust linkage.
2. Rear Clutch Dragging/Warped Welded. 2. Disassemble and repair.
3. Valve Body Malfunction. 3. Perform hydraulic pressure test to
determine cause and repair as required.
BUZZING NOISE 1. Fluid Level Low 1. Add fluid and check for leaks.
2. Shift Cable Misassembled. 2. Route cable away from engine and bell
housing.
3. Valve Body Misassembled. 3. Remove, disassemble, inspect valve
body. Reassemble correctly if necessary.
Replace assembly if valves or springs are
damaged. Check for loose bolts or
screws.
4. Pump Passages Leaking 4. Check pump for porous casting, scores
on mating surfaces and excess rotor
clearance. Repair as required. Loose
pump bolts.
5. Cooling System Cooler Plugged. 5. Flow check cooler circuit. Repair as
needed.
6.Overrunning Clutch Damaged. 6. Replace clutch.
SLIPS IN REVERSE
ONLY1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Gearshift Linkage Misadjusted. 2. Adjust linkage.
3. Rear Band Misadjusted. 3. Adjust band.
4. Rear Band Worn. 4. Replace as required.
5. Hydraulic Pressure Too Low. 5. Perform hydraulic pressure tests to
determine cause.
6. Rear Servo Leaking. 6. Air pressure check clutch-servo
operation and repair as required.
7. Band Linkage Binding. 7. Inspect and repair as required.
21 - 28 AUTOMATIC - 31THRS
AUTOMATIC - 31TH (Continued)