spark plugs replace ISUZU TROOPER 1995 Workshop Manual

MILEAGE
ONL
V
ITEMS MILEAGE
ONLY
ITEMS
7.5
1
CHANGE
FRONT
AND
REAR AXLE
OIL
2
CHANGE
MANUAL
TRANSMISSION
AND
TRANSFER CASE
OIL
3
REPLACE AIR
CLEANER FILTER
4
REPLACE SPARK PLUGS
5
CHANGE ENGINE
COOLANT
6
*REPLACE
TIMING
BELT
7
ROT
ATE
TIRES
8
CHANGE
POWER STEERING FLUID
9
REPACK FRONT
WHEEL
BEARINGS
10
REPACK FRONT
FREE-WHEELING HUBS
11
CLEAN
RADIATOR
CORE
AND
AIR CONDITIONING CONDENSER
12
INSPECT SPARK PLUG WIRE
'
-----
* : Replacement
of the
timing
belt
is recommended
at every
60,000
miles
(96,000
km).
Failure
to replace
the timing
belt
may
result
in damage to the engine.
)
•
IN THOUSANDS
OF
MILES
(USE
ODOMETER
READING)
15 22.5
30
37.5 45 52.5
60
67.5
75
82.5
90
97.5
'
-
'---
~--·-L....
SHADED AREA
INDICATES SERVICE TO
BE
PERFORMED.
)
105
112.5
120 '-------
(x 1000
miles)
DESCRIPTION ------
)
0 ~ s: l> ~ z l> z 0 m l> z c r­c m :a c; ~ 0 2

OB-4 MAINTENANCE AND LUBRICATION
EXPLANATION OF COMPLETE VEHICLE
MAINTENANCE
SCHEDULE
Brief explanations of the services listed in the
preceeding Maintenance Scheduled are presented
below.
Replace
all questionable parts and note any necessary
repairs
as you perform these maintenance
procedures.
FRONT AND REAR AXLE LUBRICANT
REPLACEMENT
Check the lubricant level after every 7,500 miles
(12,000 km) of operation and add lubricant to level
of filler hole if necessary.
Replace the front and rear
axle lubricant at 15,000
miles (24,000 km) and 30,000 miles (48,000 km) and
after every 30,000
miles (48,000 km) or operation
thereafter.
MANUAL TRANSMISSION LUBRICANT
REPLACEMENT
Check the lubricant level after every 7,500 miles
(12,000 km) of operation and add lubricant to level
of filler hole if necessary.
Replace the transmission
lubricant at 15,000 miles
(24,000 km) and 30,000 miles (48,000 km) and after
every 30,000
miles (48,000 km) of operation there­
after.
TRANSFER CASE LUBRICANT
REPLACEMENT
Check the lubricant level after every 7,500 miles
(12,000 km) of operation and add lubricant to level
of filler hole if necessary.
Replace
the transfer case lubricant at 15,000 miles
(24,000 km) and 30,000 miles (48,000 km) and after
every 30,000
miles (48,000 km) of operation there­
after.
AIR CLEANER ELEMENT REPLACEMENT
Replace the air cleaner under normal operating
conditions every 30,000 miles (48,000 km).
Operation
of the vehicle in dusty areas will
necessitate more frequent replacement.
SPARK PLUG REPLACEMENT
Replace the plugs at 30,000 mile (48,000 km) intervals
with the type specified at the end of this section.
COOLING SYSTEM SERVICE
Drain, flush and refill system with new engine coolant.
Refer
to "Recommended Fluids and Lubricants" in
this section,
or ENGINE COOLING (SEC. 68).
TIMING BELT REPLACEMENT
Replacement of the timing belt is recommended at
every 60,000 miles (96,000 km).
Failure
to replace the timing belt may result in serious
damage
to the engine.
TIRE ROTATION
Rotate tires every 7,500 miles (12,000 km).
POWER STEERING FLUID REPLACEMENT
Drain the power steering fluid and then refill the
system
to the proper level with power steering fluid
after every 30,000 miles (48,000 km) of operation.
See the appropriate section
of this manual for further
details.
FRONT WHEEL HUBS LUBRICANT
REPLACEMENT
Clean and repack the front wheel bearings at 30,000
mile (48,000 km) intervals.
Clean and lubricate the free wheeling hubs at the
same
time the front wheel bearings are serviced.
Refer
to FRONT DRIVING AXLE (SEC. 4C).
RADIATOR CORE AND AIR CONDITIONING
CONDENSER CLEANING
Clean the front of the radiator core and air con­
ditioning condenser, at 60,000 mile (96,000 km)
intervals.
SPARK PLUG WIRE INSPECTION
Check the spark plug wires at 60,000 mile (96,000 km)
intervals.
..

ENGINE DIAGNOSIS S-1
ENGINE
CONTENTS
Engine General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section S
General
Engine Mechanical .................................................... Section SA
3.2L VS Engine ............................................................... Section SA1
Engine Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section S8
Engine Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section SC
Engine Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section SD
Driveability and Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section SE2
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section SF
SECTION 6
ENGINE GENERAL INFORMATION
CONTENTS
Description of Engine Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-1
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-2
Engine Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-2
DESCRIPTION OF ENGINE SECTION
SECTIONS-ENGINE GENERAL INFORMATION SECTION S8-ENGINE COOLING
General description
Engine cleanliness and care, and general information
on engine service are covered in this section.
Engine diagnosis
This section covers the components of the fuel,
ignition, and mechanical systems that could cause a
particular complaint, and then outlines repairs in a
logical sequence.
SECTION SA-ENGINE MECHANICAL
This section contains information on the mechanical
parts of the engine, such as cylinder block, cylinder
head, crankshaft, pistons, valve train, camshaft, and
engine
lubrication.
Overhaul
procedures, removal and replacement
procedures, and specifications are also covered.
Specific subsections are:
SA-GENERAL;
Disassembly and reassembly procedures,
inspection and repair procedures
off the vehicle.
6A 1-3.2L V6 ENGINE;
Removal
and replacement procedures on the
vehicle.
Engine cooling system components such as radiator,
engine
coolant pump, thermostat, and cooling fan, are
covered
in this section.
SECTION SC-ENGINE FUEL
This section contains information on all the parts of the
fuel system except the fuel injectors, or throttle body II
unit itself. Items covered are: fuel tank, fuel pump, fuel
filter,
and fuel lines. Specific sections are used for each
fuel system type:
Port
Injection fuel rail and injectors will be found in
Section
6E2.
SECTION SD-ENGINE ELECTRICAL
Items covered in this section are battery, generator,
starter, ignition
coil, spark plugs and wires.
Ignition system diagnosis will be found in Section 6E2
as a "C4" chart.
Specific sections are:
601 -Battery
602 - Cranking System
603 -Charging System
604 -Ignition System

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.

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)
•

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
•

ENGINE DIAGNOSIS 6-11
ENGINE NOISY (Cont'd)
Condition Possible cause Correction
Timing belt noise
Timing belt tension is incorrect Replace pusher or adjust the
ajust
pulley or replace timing
belt
Tensioner bearing defective Replace
Timing belt defective Replace
Timing wheels defective Replace
Timing belt comes in contact with Replace timing belt and timing
timing cover
cover
Valve noise Valve clearance incorrect Replace HLA
Valve and valve guide seized Replace valve and valve guide
Valve spring broken Replace
Valve
seat off-positioned
Correct
Crankshaft noise
Crankshaft end
play excessive (noise Replace thrust bearing
occurs
when clutch is engaged)
Engine knocking
Preignition due
to use of spark plugs of Install Spark Plugs of adequate
inadequate heat range
heat range
Carbon deposits in combustion
Clean
chambers
Fuel too low in octane rating Replace fuel
Wide Open Throttle enrichment system
Refer to Section 6E2
failure
Selection
of transmission gear incorrect Caution operator of incorrect
gear
selection
Engine overheating
Refer to "Engine Lacks Power"
Others Water
pump defective Replace
Drive belt slipping Adjust tension of drive belt or
replace drive belt

6A-2 GENERAL ENGINE MECHANICAL
NOTE:
•
During disassembly, be sure that the valve train
components are kept
together and identified so
that they can be re-installed in their original
locations.
• Before removing the cylinder head from the
engine and before disassembling the valve
mechanism, perform a compression test and note
the results.
1•! .. 1 DISASSEMBLY
(SOHC)
1. Camshaft timing pulley
2. Front plate
3. Camshaft bracket fixing bolts
4. Camshaft, oil seal and camshaft end plug
• Remove them with camshaft bracket.
5. Rockershaft assembly (Exhaust side)
6. Rockershaft assembly (Intake side)
7. Spark plug
\fl CAUTION:
VI • Do not remove the spark plugs when the head
and plugs are hot.
• Clean dirt and debris from spark plug recess
areas.
(DOHC)
1. Camshaft timing pulley
2. Front plate
3. Camshaft bracket fixing bolts
4. Chain tensioner fixing bolts
5. Camshaft, oil seal and camshaft end plug
• Remove them with chain and chain tensioner
6. Swing arm.
7. Hydraulic lash adjusters (HLA)
NOTE:
Immerse HLA in engine oil, taking care nottoturn it
upside down or sideways in order to prevent any
air
from entering into HLA.
8. Spark plug
\flCAUTION:
VI • Do not remove the spark plugs when the head
and plugs are hot.
• Clean dirt and debris from spark plug recess
areas.
f}l CLEAN
• Cylinder head
Carefully remove
all varnish, soot and carbon
to the bare metal. Do not use a motorized wire
brush on any gasket sealing surface.
IL'~'IINSPECTION AND REPAIR
• Cylinder head gasket and mating surfaces for
leaks, corrosion and blow-by. If the gasket has
failed, determine the cause. Insufficient
torque on head bolts
Improper installation
Loose
or warped cylinder head
Missing
dowel pins
- Warped case surface
1. Cylinder head bolts for damaged threads or
stretching and damaged heads caused by
improper use of tools.
\fl CAUTION:
VI Replace used cylinder head bolts.
2. Cylinder head for cracks, especially between valve
seats and in the exhaust ports.
3. Cylinder head deck for corrosion, sand particles in
head and porosity.
\fl CAUTION:
VI Do not attemptto weld the cylinder head. Replace
it.
4. Cylinder head deck, intake and exhaust manifold
mating surfaces for flatness (Fig. 6A-2). These
surfaces
may be re-conditioned by milling. If the
surfaces are
"out of flat" by more than
specification, the surface should be ground
to
within specifications. If more than repairable limit
of specification, it should be replaced.
5. Water jacket sealing plugs seating surfaces.
IIVD1-w 8~
~ I 0 I ' 0 0 I 0
mm (in)
Warpage
Maximum
Standard Repairable limit limit
Head surface 0.05 (0.002) 0.2
0.2
Manifold surface or less (0.00787) (0.00787)
SOHC 104.8 0.2
104.6
Head (4.1260) (0.00787) (4.1181)
height
DOHC 137.5 0.2 137.3
(5.4134)
(0.00787) (5.4055)
Fig. 6A-2
•

IGNITION SYSTEM 604 - 3
ON-VEHICLE SERVICE
SPARK PLUG WIRES
EJ REMOVAL
Preparation
• Disconnect battery ground cable.
1. Spark plug wires (Fig. 604-2)
Fig. 6D4-2
(1!] INSPECTION AND REPAIR
Check the high tension cable for insulation. Check
terminals for corrosion or damage, and replace as
necessary.
Measuring resistance of spark plug wires (kQ)
Spare plug wires SOHC DOHC
No.1 cable 6.4-14.9 6.2-14.2
No.2 cable 5.7-13.1 7.2-16.7
No.3 cable 6.2-14.4 6.5-14.9
No.4 cable 5.8-13.3 6.8-15.8
No.5 cable 6.4-14.9 6.9-16.0
No.6 cable 6.9-16.0 6.3-14.5
Measure resistance
of spark plug wires, and replace
the cable if its value exceeds the standard. (Fig. 6D4-
3)
Fig. 6D4-3
B INSTALLATION
1. Spark plug wires
• Connect ignition coils and spark plugs with
spark plug wires respectively. Match each
number (cylinder No.) marked on the ignition
coil with that on spark plug wire, and connect
each spark
plug for the cylinder. (Fig. 6D4-4)
LH bank
y Front
#4-­
#1--
1®®®1
RH Bank
Connecting Position of Spark plug wire
Fig. 6D4-4
• Connect battery ground cable.
"f CAUTION
Do not cross, twist or pull the spark plug wires.
SPARK PLUG
EJ REMOVAL
1. Spare plug wires
2. Spark plugs (Fig. 604-5)

604-4 IGNITION SYSTEM
Fig. 604A-5
~ INSPECTION AND REPAIR
The spark plug affects entire engine performance and
therefore its inspection is very important.
• Check electrode and insulator for presence of
crack, and replace if any.
• Check electrode for wear, and replace if neces­
sary.
• Check gasket for damage, and replace if neces­
sary.
• Measure insulation resistance with an ohmmeter,
and replace if faulty.
• Adjust spark plug gap to 1.0(0.04) -1.1 (0.043)
mm(in).
• Check fuel and electrical systems if spark plug is
extremely dirty.
• Use spark plugs having low heat value (hot type
plug) if fuel and electrical systems are normal.
• Use spark plugs having high heat value (cold type
plug) if insulator and electrode are extremely
burned.
Sooty spark plugs
Much deposit of carbon or oil on the electrode and
insulator of spark plug reduces the engine perfor­
mance.
Possible causes:
• Too rich mixture
• Retarded ignition timing
• Presence of oil in combustion chamber
• Incorrectly adjusted spark plug gap
Burning electrodes
This fault is characterized by scorched or heavily
oxidized electrode or blistered insulator nose.
Possible causes:
• Too lean mixture
• Advanced ignition timing
• Improper heat value
Measuring Insulation Resistance
• Measure insulation resistance using a 500 volt
megaohm meter. (Fig. 604-6)
Fig.
604-6
• Replace spark plugs if measured value is out of
standard.
I @!.j Insulation resistance MQ 50 or more
Cleaning Spark Plugs
• Clean spark plugs with a spark plug cleaner.
• Raise the ground electrode to an angle of 45 to 60
degrees. If electrode is wet, dry it before cleaning.
• After spark plug is thoroughly cleaned, check
insulator for presence of crack.
• Clean threads and metal body with a wire brush.
• File the electrode tip if electrode is extremely
worn.
• Bend the ground electrode to adjust the spark
plug gap. (Fig. 604-7)
Fig. 604-7
•