fuel pressure ISUZU TROOPER 1995 Workshop Manual

OA-10 GENERAL INFORMATION
ABBREVIATIONS CHARTS
LIST OF AUTOMOTIVE ABBREVIATIONS WHICH MAY BE USED IN THIS MANUAL
A-Ampere(s)
ABS-Anti lock Brake System
AC-Alternating Current
A/C-Air Conditioning
ACCEL-Accelerator
ACC-Accessory
ACL-Air Cleaner
Adj-Adjust
A/F-Air Fuel Ratio
AIR-Secondary Air Injection System
Alt-Altitude
AMP-Ampere(s)
ANT-Antenna
ASM-Assembly
A/T-Automatic Transmission/Transaxle
ATDC-After Top Dead Center
ATF-Automatic Transmission Fluid
Auth -Authority
Auto -Automatic
BARO-Barometric Pressure
Bat -Battery
B+-Battery Positive Voltage
Bbl-Barrel
BHP-Brake Horsepower
BPT-Backpressure Transducer
BTDC-Before Top Dead Center
oc-Degrees Celsius
CAC-Charge Air Cooler
Calif-California
cc-Cubic Centimeter
CID-Cubic Inch Displacement
CKP-Crankshaft Position
CL-Closed Loop
CLCC-Closed Loop Carburetor Control
CMP-Camshaft Position
CO-Carbon Monoxide
Coax-Coaxial
Conn-Connector
Conv -Converter
Crank-Crankshaft
Cu.ln.-Cubic Inch
CV-Constant Velocity
Cyl-Cylinder(s)
Dl -Distributor Ignition
Diff-Differential
Dist-Distributor
DLC-Data Link Connector
DOHC-Double Overhead Camshaft
DTC-Diagnostic Trouble Code
DTM-Diagnostic Test Mode
DTT-Diagnostic Test Terminal
DVM-Digital Voltmeter (10 meg.)
DVOM-Digital Volt Ohmmeter
EBCM-Electronic Brake Control Module
ECM-Engine Control Module
ECT-Engine Coolant Temperature
EEPROM -Electronically Erasable Programmable
Read Only Memory
EGR-Exhaust Gas Recirculation
El-Electronic Ignition
ETR-Electronically Tuned Receiver
EVAP-Evaporation Emission
Exh-Exhaust
°F-Degrees Fahrenheit
Fed -
Federal (All States Except Calif.)
FF-Front Drive Front Engine
FL-Fusible Link
FLW-Fusible Link Wire
FP-Fuel Pump
FRT-Front
ft-Foot
FWD-Front Wheel Drive
4WD-Four Wheel Drive
4 x
4-Four Wheel Drive
4 A/T-Four Speed Automatic Transmission/
Transaxle
Gal-Gallon
GEN-Generator
GND-Ground
Gov-Governor
g-Gram
Harn -Harness
HC-Hydrocarbons
HD-Heavy Duty
Hg-Hydrargyrum (Mercury)
HiAit-High Altitude
H02S - Heated Oxygen Sensor
HVAC-Heater-Vent-Air Conditioning
lAC-Idle Air Control
IAT -Intake Air Temperature
IC-Integrated Circuit
-
Ignition Control
ID-Identification
-Inside Diameter
IGN-Ignition
INJ-Injection
IP-Instrument Panel
IPC-Instrument Panel Cluster
lnt-Intake
ISC-Idle Speed Control
J/B-Junction Block
kg -Kilograms
km-Kilometers
km/h -Kilometer per Hour
kPa-Kilopascals
kV-Kilovolts (thousands of volts)
kW-Kilowatts
KS -Knock Sensor
L-Liter
lb·ft-Foot Pounds
lb·in-Inch Pounds

LF -Left Front
LH -Left Hand
LR-Left Rear
LS-Left Side
LWB-Long Wheel Base
L-4-In-line Four Cylinder Engine
MAF-Mass Air Flow
MAN-Manual
MAP-Manifold Absolute Pressure
Max-Maximum
MC-Mixture Control
MFI-Multipart Fuel Injection
MIL-Malfunction Indicator Lamp
Min-Minimum
mm-Millimeter
MPG-Miles per Gallon
MPH-Miles per Hour
M!f-Manual Transmission!fransaxle
MV-Millivolt
NA-Natural Aspirated
NC-Normally Closed
N·m-Newton Meters
NO-Normally Open
NOx-Nitrogen, Oxides of
OBD-On-Board Diagnostic
OD-Outside Diameter
0/D-Over Drive
OHC-Overhead Camshaft
OL-Open Loop
02-Oxygen
02S -Oxygen Sensor
PAIR-Pulsed Secondary Air Injection System
P/B-Power Brakes
PCM-Powertrain Control Module
PCV-Positive Crankcase Ventilation
PRESS-Pressure
PROM-Programmable Read Only Memory
PNP-Park/Neutral Position
P/S-Power Steering
PSI-Pounds per Square Inch
PSP-Power Steering Pressure
Pt.-Pint
Pri -Primary
PWM-Pulse Width Modulate
Ot-Quart
REF-Reference
RF -Right Front
RFI-Radio Frequency Interference
RH-Right Hand
RPM-Revolutions per Minute
RPM Sensor-Engine Speed Sensor
RPO-Regular Production Option
RR-Right Rear
RS-Right Side
RTV-Room Temperature Vulcanizing
RWAL-Rear Wheel Anti lock Brake
RWD-Rear Wheel Drive
GENERAL INFORMATION OA-11
SAE -Society of Automotive Engineers
Sec-Secondary
SFI-Sequential Multipart Fuel Injection
Sl-System International
SIR-Supplemental Inflatable Restraint System
SOHC-Single Overhead Camshaft
Sol -Solenoid
SPEC -Specification
Speedo -Speedometer
SRS-Supplemental Restraint System
ST-Start
-Scan Tool
Sw-Switch
SWB-Short Wheel Base
SYN-Synchronize
Tach-Tachometer
TB
-Throttle Body
TBI-Throttle Body Fuel Injection
TCC-Torque Converter Clutch
TCM-Transmission Control Module
TDC-Top Dead Center
Term-Terminal
TEMP-Temperature
TP-Throttle Position
TRANS-Transmission!fransaxle
TURBO-Turbocharger
TVRS-Television & Radio Suppression
TVV-Thermal Vacuum Valve
TWC-Three Way Catalytic Converter
3
AfT-Three Speed Automatic Transmission/
Transaxle
2WD-Two Wheel Drive
4 x
2-Two Wheel Drive
U-joint-Universal Joint
V-Volt(s)
VAC-Vacuum
VIN-Vehicle Identification Number
VRRRE -Vehicle Refrigerant Recovery and Recycling
Equipment
V-ref-ECM Reference Voltage
VSS-Vehicle Speed Sensor
VSV-Vacuum Switch Valve
V-6-Six Cylinder "V" Engine
V-8-Eight Cylinder "V" Engine
W-Watt(s)
w/-With
w/b -Wheel Base
w/o -Without
WOT-Wide Open Throttle

FLUID LEVEL CHECK
A fluid loss in any system (except windshield
washer) may indicate a problem. Repair the system
at once.
Engine
oil level -Check level and add if
necessary. The best time to check the engine oil
level is
when the oil is warm. After stopping the
engine with the vehicle on a level surface, wait a
few minutes for the oil to drain back to the oil pan.
Pull
out the oil level indicator (dipstick). Wipe it
clean and push the oil level indicator back down all
the
way. Pull out the oil level indicator, keeping the
tip down, and look at the oil level on it.
Add oil, if needed, to keep the oil level above
the
"ADD" mark and between the "ADD" and
"FULL" marks in the operating range area. Avoid
overfilling the engine since this may cause engine
damage. Push
the oil level indicator back down all
the
way after taking the reading.
If you check the oil level when the oil is cold, do
not run the engine first. The cold oil will not drain
back
to the pan fast enough to give a true oil level.
Engine coolant level and condition -Check
engine coolant level in the coolant reservoir and
add engine
coolant if necessary. Inspect the engine
coolant and replace it if dirty or rusty.
Windshield washer fluid level -Check washer
fluid level in reservoir and add if necessary.
Power steering system reservoir level-Check
and keep at
proper level.
Brake master cylinder reservoir level -Check
fluid. Keep fluid at proper level. A low fluid level
can indicate
worn disc brake pads which may need
to be serviced.
Hydraulic clutch system -Check fluid l~vel in
the reservoir.
Add fluid as required.
Battery fluid level -Check fluid level in the
battery.
FLUID LEAK CHECK
Check for fuel, water, oil or other fluid leaks by
looking at the surface beneath the vehicle after it
has been parked for a while. Water dripping from
the air conditioning system after use is normal. If
you notice gasoline fumes or fluid at any time,
locate the source and correct it at once.
ENGINE OIL AND OIL FILTER
REPLACEMENT
Always use API SE, SF, SG, SH or ILSAC GF-1
quality oils of the proper viscosity.
When choosing an oil, consider the range of
temperatures the car will be operated in before the
next oil change. Then, select the recommended oil
viscosity
from the chart (Fig. OB-1).
Always change the oil and the oil filter as soon as
possible after driving in a dust storm.
MAINTENANCE AND LUBRICATION OB-5
ENGINE COOLING SYSTEM INSPECTION
Inspect coolant/anti-freeze. If coolant is dirty or
rusty, drain, flush and refill with new coolant. Keep
coolant at the proper mixture for proper freeze
protection,
corrosion inhibitor level and best engine
operating temperature.
Inspect hoses and replace if
cracked, swollen or deteriorated. Tighten hose
clamps if equipped with screw-type clamps. Clean
outside of radiator and air conditioning condenser.
Wash
filler cap and neck. To help ensure proper
operation, a pressure test of both the cooling
system and cap is also recommended.
EXHAUST SYSTEM INSPECTION
Visually inspect the exhaust pipes, muffler, heat
shields and hangers
for cracks, deterioration, or
damage.
Be alert to any changes in the sound of the exhaust
system
or any smell of fumes. These are signs the
system may be leaking or overheating. Repair the
system at once,
if these conditions exist. (See also
"Engine Exhaust Gas Safety" and "Three Way
Catalytic Converter" in Owner's manual.)
FUEL CAP, FUEL LINES, AND FUEL TANK
INSPECTION
Inspect the fuel tank, the fuel cap and the fuel lines
every
60,000 miles (96,000 km) for damage which
could cause leakage.
Inspect the fuel cap and the gasket for correct sealing
and physical damage. Replace any damaged parts.
DRIVE BELT INSPECTION
Check the belts driving the steering oil pump, the air
conditioning compressor, and the generator
for
cracks, fraying, wear, and correct tension every 30,000
miles (48,000 km). Adjust or replace as necessary.
WHEEL ALIGNMENT, BALANCE AND
TIRES OPERATION
Uneven or abnormal tire wear, or a pull right or left
on a straight and level road may show the need for
a wheel alignment. A vibration of the steering
wheel or seat at normal highway speeds means a
wheel balancing is needed. Check tire pressure
when the tires are "cold" (include the spare).
Maintain pressure as shown in the tire placard,
which is located on the driver's door lock pillar.
STEERING SYSTEM OPERATION
Be alert for any changes in steering action. An
inspection
or service is needed when the steering
wheel is harder
to turn or has too much free play, or
if there are unusual sounds when turning or parking.

INFLATION OF TIRES
Tire pressure, in cold condition (after vehicle has setfor
three hours or more, and driven less than one mile),
should
be checked monthly or before any extended
trip. Tire pressure increases
approximately 15% when
the tires become hot during driving. Tire pressure
specification is shown on the
label located on the left
door lock pillar (Fig. 3E-5).
Fig.
3E-5
NOTE:
Check the tire pressure whenever irregular wear is
found. Tire
inflation greatly affects tire wear. If the
alignment check does not reveal any alignment
problems,
check the condition of the shock absorbers
and
wheel/tire balance.
WHEELS AND TIRES 3E-3
DIAGNOSIS LIST
If the following conditions are noted, rotation is
required.
1. Front tire wear is different from rear.
2. Uneven wear exists across the tread of any tire.
3. Left and right front tire wear is unequal.
4. Left and right rear tire wear is unequal.
If
the following conditions are noted, check the wheel
alignment.
1. Left and right front tire wear is unequal.
2. Uneven wear exists across the tread of any tire.
3. Front tire treads have scuffed appearance with
"feather" edges on one side of tread ribs or
blocks.
4. There is cupping, flat spotting etc.
Higher than recommended pressure can cause:
1. Hard ride.
2. Poor steering stability.
3. Rapid and uneven wear at center of the tread.
Lower than recommended pressure can cause:
1. Tire squeal on turns.
2. Hard steering.
3. Rapid and uneven wear on the edges of the tread.
4. Tire rim bruises and rupture.
5. Tire cord breakage.
6. High tire temperatures.
7. Reduced handling.
8. Reduced fuel economy.
Unequal pressure on same axle can cause:
1. Uneven braking
2. Steering lead.
3. Reduced handling.
4. Swerve on acceleration

6-2 ENGINE DIAGNOSIS
SECTION 6E-DRIVEABILITY
AND EMISSIONS
This section covers emission control systems general
information, and diagnostic procedures which will lead
to repairing performance and driveability related
problems.
Emission components are covered, as well
as removal and replacement procedures.
Instructions on use
of special tools are also given.
SECTION 6F-ENGINE EXHAUST
This section has information on all exhaust system
parts, such
as tailpipes, mufflers, and the catalytic
converter.
GENERAL DESCRIPTION
ENGINE CLEANLINESS AND CARE
An automobile engine is a combination of many
machined, honed,
polished and lapped surfaces with
tolerances that are measured in the thousandths of a
millimeter (ten thousandths of an inch). Accordingly,
when any
internal engine parts are serviced, care and
cleanliness are important. Throughout this section, it
should be understood that proper cleaning and
protection
of machined surfaces and friction areas is
part
of the repair procedure. This is considered
standard shop practice even
if not specifically stated.
• A liberal coating of engine oil should be applied to
all friction areas during assembly to protect and
lubricate the surfaces on initial operation.
• Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and
crankshaft
journal bearings are removed for
service, they should be retained in order.
• At the time of installation, they should be installed
in the same locations and with the same mating
surfaces
as when removed.
• Battery cables should be disconnected before any
major
work is performed on the engine. Failure to
disconnect
cables may result in damage to wire
harness
or other electrical parts.
• The six cylinders of this engine are identified by
numbers; Right side
cylinders 1, 3 and 5, Left side
cylinders 2, 4 and 6, as counted from crankshaft
pulley side to flywheel side.
GENERAL INFORMATION ON ENGINE
SERVICE
The following information on engine service should be
noted
carefully, as it is important in preventing damage
and contributing
to reliable engine performance.
• When raising or supporting the engine for any
reason,
do not use a jack under the oil pan. Due to
the
small clearance between the oil pan and the oil
pump strainer, jacking against the oil pan may
cause damage to the
oil pick-up unit.
• The 12-volt electrical system is capable of
damaging circuits. When performing any work
where electrical terminals could possibly be
grounded, the ground cable of the battery should
be disconnected at the battery.
• Any time the intake air duct or air cleaner is
removed, the intake opening
should be covered.
This
will protect against accidental entrance of
foreign material into the cylinder which could
cause extensive damage when the engine is
started.
ENGINE DIAGNOSIS
CONTENTS
Hard Starting . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Engine Compression
Test Procedure ..... 6-4
Rough Engine
Idling or Engine Stalling . . . 6-5
Rough Engine Running . . . . . . . . . . . . . . . . .
6-6
Hesitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Engine Lacks
Power . . . . . . . . . . . . . . . . . . . . 6-8
Engine
Noisy .......................... 6-10
Abnormal Combustion . . . . . . . . . . . . . . . . . . 6-12
Engine Oil Consumption Excessive . . . . . . . 6-13
Fuel Consumption Excessive ............. 6-14
Oil Problems . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Malfunction Indicator Lamp . . . . . . . . . . . . . . 6-15
Engine Oil Pressure Check ............... 6-16
Inspection of Hydraulic Lash Adjuster . . . . . 6-17

6-4 ENGINE DIAGNOSIS
HARD STARTING (Cont'd)
4. Engine lacks compression
Condition Possible cause
Spark plug loosely fitted or spark plug
gasket defective
Valve timing incorrect
Cylinder head gasket defective
Valve incorrectly seated
Valve stem seized
Valve spring weakened
Cylinder or piston rings worn
Piston ring seized
ENGINE COMPRESSION TEST
PROCEDURE
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and
fuse box.
6. Engage the starter and check that the cranking
speed is approximately
300 rpm.
7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the
starter engaged
until the compression gage
needle reaches the
maximum level. Note the
reading.
9. Repeat the test with each cylinder.
If
the compression pressure obtained falls below the
limit, engine overhaul is necessary.
Limit; 883
kPa (128 psi) Correction
Tighten
to specified torque or
replace gasket
Adjust
Replace gasket
Lap
valve
Replace valve
and valve guide
Replace
Overhaul engine
Overhaul engine.

ENGINE DIAGNOSIS 6-5
ROUGH ENGINE IDLING OR ENGINE STALLING
Condition Possible cause Correction
Trouble in fuel
Idle air control valve defective Replace
injection system
Throttle shutting
off incomplete Correct or replace
Throttle position sensor circuit open
or shorted Correct or replace
Fuel injector circuits open or shorted Correct or replace
Fuel injectors damaged
Replace
Fuel pump relay defective Replace
Manifold Absolute Pressure Sensor
cable Correct or replace
disconnected
or broken
Manifold Absolute Pressure Sensor defective
Replace
Engine Coolant Temperature Sensor cable Correct
or replace
disconnected
or broken
Engine Coolant Temperature Sensor defective
Replace
Intake Air Temperature sensor cable Correct or replace
disconnected
or broken
Intake Air Temperature sensor defective
Replace
Knock Sensor
(KS) circuits open or shorted
Correct or replace
(DOHC only)
KS defective (DOHC only) Replace
KS Module circuits open or ground
Correct or replace
(DOHC only)
KS Module defective (DOHC only) Replace
Vehicle Speed Sensor circuit open or shorted
Correct or replace
Vehicle Speed Sensor defective
Replace
Trouble in emission
Engine Control Module defective
Replace
control system
Exhaust Gas Recirculation
Valve faulty
Replace
Back Pressure Transducer defective
Replace
Vacuum Switch Valve (VSV); EGR circuit
Correct
open
VSV; EGR defective Replace
Canister purge
VSV circuit open
Correct
VSV; canister circuit open
Correct
VSV; canister defective
Replace
Evaporative Emission Canister Purge control
Replace
valve defective
Trouble in ignition system
Refer
to Hard Start
Troubleshooting Guide
Others Engine lacks compression
Refer to Hard Start
Troubleshooting Guide
Valve incorrectly seated
Lap valve
Air Cleaner Filter clogged
Replace filter element
Valve timing incorrect
Readjust
Idle air control valve broken
Replace
Fast
idle solenoid defective
Replace
Positive Crankcase Ventilation valve defective
or Replace
clogged

6-6 ENGINE DIAGNOSIS
ROUGH ENGINE RUNNING
Complaint
Faulty parts Possible cause Correction
Engine misfires Ignition coil
Coil layer shorted Replace
regularly
high-tension Primary lead wire broken leakage due
Correct cables to defective insulator
Spark plugs
Fouling Clean
or install hotter type
plug
Insulator
nose leaking Replace
Fuel
injectors Fuel injector(s) defective Replace
Dropping register defective Replace
Engine Control
Faulty Replace
Module
Engine knocks Spark plugs
Spark plugs running too hot Install colder type spark
regularly
plugs
Engine Control Faulty
Replace
Module
Engine lacks Spark plugs
Fouled Clean
power Multipart Fuel
Fuel injectors defective Replace
Injection Manifold Absolute Pressure (MAP)
Correct or replace system Sensor or Manifold Absolute Pressure
Sensor
circuit defective
Engine
Coolant Temperature Sensor or Correct or replace
Engine Coolant Temperature Sensor
circuit dcefective
Engine
Control Module faulty Replace
Intake
Air Temperature Sensor or Intake
Air Temperature Sensor circuit Correct or replace
defective
Throttle Position Sensor or Throttle Correct or replace
Position Sensor
circuit defective
Knock
Sensor or Knock Sensor circuits Correct or replace
defective (DOHC only)
Knock Sensor Module or Knock Sensor Correct or replace .
Module
circuits defective (DOHC only)
•

ENGINE DIAGNOSIS 6-7
HESITATION
Condition Possible cause Correction
Hesitation on Throttle
Position Sensor adjustment incorrect Replace
throttle
acceleration valve
assembly
Throttle Position Sensor circuit open
or shorted Correct
or replace
Excessive play in accelerator linkage
Adjust or replace
Manifold Absolute
Pressure (MAP) Sensor circuit open or shorted Correct or replace
MAP Sensor defective Replace
Intake Air
Temperature (IAT) Sensor circuit open or shorted Correct or replace
Knock Sensor
(KS) Circuit open or shorted (DOHC only) Correct or replace
KS defective (DOHC only) Replace
KS Module circuits open or shorted (DOHC only) Correct or replace
KS Module defective (DOHC only) Replace
IAT Sensor defective Replace
Hesitation at
Fuel pressure
too low
high speeds
Fuel tank strainer clogged Clean or replace
Fuel pipe clogged
Clean or replace
Fuel filter clogged
Replace
Defective fuel
pump system Check and replace
Fuel Pressure Control Valve leaking Replace
Fuel injector
not working normally
Power supply or ground circuit for Multipart Fuel Injection Check and correct or
System shorted or open
replace
Distributor defective Replace
Cable of Multipart Fuel Injection System disconnected or defective Correct or replace
Engine Control Module defective Replace
Throttle Position Sensor circuit open
or shorted Correct or replace
Throttle Position Sensor defective Replace
Engine Coolant Temperature Sensor circuit open
or shorted Correct or replace
Engine Coolant Temperature Sensor defective Replace
MAP Sensor cable open
or shorted Correct or replace
MAP Sensor defective
Replace
IAT Sensor circuit open or shorted
Correct or replace
IAT Sensor defective Replace
KS Circuit open or shorted (DOHC only)
Correct or replace
KS defective (DOHC only) Replace
KS Module circuit open or shorted (DOHC only) Correct or replace
KS Module defective (DOHC only) Replace
Throttle valve
not wide opened
Check and correct or
replace
Air Cleaner Filter clogged
Replace filter element
Power supply voltage
too low Check and correct or
replace

6-8 ENGINE DIAGNOSIS
ENGINE LACKS POWER
Condition
Possible cause Correction
Trouble in fuel system Fuel Pressure Control Valve not Replace
working normally
Fuel
injector clogged Clean or replace
Fuel
pipe clogged Clean
Fuel filter clogged
or fouled Replace
Fuel
pump drive circuit not working Correct or replace
normally
Fuel tank not sufficiently breathing due Clean or replace
to clogged Evaporative Emission
Control System circuit
Water in
fuel system Clean
Inferior quality fuel
in fuel system Use fuel of specified octane
rating
Engine
Control Module supplied poor Correct circuit
voltage
Throttle
Position Sensor cable Correct or replace
disconnected or broken
Throttle Position Sensor defective Replace
Manifold Absolute
Pressure Sensor not Replace
working normally
Intake Air Temperature Sensor not Replace
working normally
Engine Coolant Temperature Sensor Correct or replace
circuit open or shorted
Engine
Coolant Temperature Sensor Replace
defective
Engine
Control Module defective Replace
Trouble
in intake or exhaust Air Cleaner Filter clogged Replace filter element
system Trouble in Induction air control valve Correct or replace
system (DOHC)
Air duct kinked or flattened Correct or replace
Ignition failure
Refer to Hard Start
Troubleshooting Guide
Heat range
of spark plug inadequate Install spark plugs of adequate
heat range
Electronic Ignition System with module Replace
•