spark plugs replace ISUZU AXIOM 2002 Service Repair Manual

0B±5 MAINTENANCE AND LUBRICATION
Explanation of Complete Vehicle
Maintenance Schedule
Brief explanations of the services listed in the preceding
Maintenance Schedule 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) of operation thereafter.
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 100,000 miles (160,000 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
ªRecommended Fluids and Lubricantsº in this
section, or ENGINE COOLING (SEC.6B).
Timing Belt Replacement
Replacement of the timing belt is recommended at every
100,000 miles (160,000 km).
Failure to replace the timing belt may result in serious
damage to the engine.
Valve Clearance Adjustment
Incorrect valve clearance will result in increased engine
noise and reduced engine output.
Retorque the camshaft bracket bolts before checking and
adjusting the valve clearance.
Check and adjust the valve clearance whenever
increased engine noise is heard.
Tire Rotation
Rotate tires every 7,500 miles (12,000 km).
Front Wheel Bearings Lubricant
Replacement (Vehicles Produced Before
July/31/2001)
Clean and repack the front wheel bearings at 30,000
miles (48,000 km) intervals.
Refer to DRIVE SHAFT SYSTEM (SEC. 4C).
Front Wheel Bearings Check (Vehicles
Produced After Aug./1/2001)
Inspect hub unit bearing at every 60,000 miles (96,000
km).
If there is abnormal condition, replace hub unit bearing.
Radiator Core and Air Conditioning
Condenser Cleaning
Clean the front of the radiator core and air conditioning
condenser, at 60,000 miles (96,000 km) intervals.
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 ªADDº
mark and between the ªADDº and ªFULLº 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 the reservoir and add if
necessary.
Power steering system reservoir level
Check and keep at the 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 level 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.

6A±5
ENGINE MECHANICAL (6VE1 3.5L)
4. Engine Lacks Compression
Condition
Possible causeCorrection
Engine lacks compressionSpark plug loosely fitted or spark
plug gasket defectiveTighten to specified torque or replace
gasket
Valve timing incorrectAdjust
Cylinder head gasket defectiveReplace gasket
Valve incorrectly seatedLap valve
Valve stem seizedReplace valve and valve guide
Valve spring weakened or brokenReplace
Cylinder or piston rings wornOverhaul engine
Piston ring seizedOverhaul engine.
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; 1000 kPa (145 psi)

6A±7
ENGINE MECHANICAL (6VE1 3.5L)
Rough Engine Running
ConditionPossible causeCorrection
Engine misfires periodicallyIgnition coil layer shortedReplace
Spark plugs foulingClean or install hotter type plug
Spark plug(s) insulator nose leakingReplace
Fuel injector(s) defectiveReplace
Powertrain control module faultyReplace
Engine knocks periodicallySpark plugs running too hotInstall colder type spark plugs
Powertrain control module faultyReplace
Ion Sensing module faultyRefer or replace
Engine lacks powerSpark plugs fouledClean
Fuel injectors defectiveReplace
Mass Airflow Sensor or Intake
Airflow Sensor circuit defectiveCorrect or replace
Manifold Absolute Pressure (MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defectiveCorrect or replace
Engine Coolant Temperature Sensor
or Engine Coolant Temperature
Sensor circuit defectiveCorrect or replace
Powertrain Control Module faultyReplace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defectiveCorrect or replace
Throttle Position Sensor or Throttle
Position Sensor circuit defectiveCorrect or replace
ION Sensing Module or ION Sensing
Module circuits defectiveCorrect or replace

6A±10
ENGINE MECHANICAL (6VE1 3.5L)
Engine Lacks Power
ConditionPossible causeCorrection
Trouble in fuel systemFuel Pressure Control Valve not
working normallyReplace
Fuel injector cloggedClean or replace
Fuel pipe cloggedClean
Fuel filter clogged or fouledReplace
Fuel pump drive circuit not working
normallyCorrect or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative
Emission Control System circuitClean or replace
Water in fuel systemClean
Inferior quality fuel in fuel systemUse fuel of specified octane rating
Powertrain Control Module supplied
poor voltageCorrect circuit
Throttle Position Sensor cable
broken or poor connectionsCorrect or replace
Throttle Position Sensor defectiveReplace
Mass Airflow Sensor not working
normallyReplace
Manifold Absolute Pressure Sensor
not working normallyReplace
Intake Air Temperature Sensor not
working normallyReplace
Engine Coolant Temperature Sensor
circuit open or shortedCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Powertrain Control Module defectiveReplace
Trouble in intake or exhaust systemAir Cleaner Filter cloggedReplace filter element
Air duct kinked or flattenedCorrect or replace
TWC defectiveRepair
Ignition failureÐÐÐÐRefer to Hard Start Troubleshooting
Guide
Heat range of spark plug inadequateInstall spark plugs of adequate heat
range
Ignition coil defectiveReplace

6A±13
ENGINE MECHANICAL (6VE1 3.5L)
Troubleshooting Procedure for Slapping or Hitting etc Noise
The slapping sound stops when spark plug on bad
cylinder is shorted out.
Condition
Possible causeCorrection
Timing belt noiseTiming belt tension is incorrectReplace pusher or adjust the tension
pulley or replace timing belt
Tensioner bearing defectiveReplace
Timing belt defectiveReplace
Timing pulley defectiveReplace
Timing belt comes in contact with
timing coverReplace timing belt and timing cover
Valve noiseValve clearance incorrectReplace adjusting shim
Valve and valve guide seizedReplace valve and valve guide
Valve spring broken or weakenedReplace
Valve seat off±positionedCorrect
Camshaft worn outReplace
Crankshaft noiseCrankshaft end play excessive
(noise occurs when clutch is
engaged)Replace thrust bearing
Engine knockingPreignition due to use of spark plugs
of inadequate heat rangeInstall Spark Plugs of adequate heat
range
Carbon deposits in combustion
chambersClean
Fuel too low in octane ratingReplace fuel
Wide Open Throttle enrichment
system failureRefer to Section 6E
Selection of transmission gear
incorrectCaution operator of incorrect gear
selection
Engine overheatingRefer to ªEngine Lacks Powerº
OthersWater pump defectiveReplace
Drive belt slippingReplace auto tensioner or drive belt

6A±50
ENGINE MECHANICAL (6VE1 3.5L)
Disassembly
NOTE:

During disassembly, be sure that the valve train
components are kept together and identified so that
they can be reinstalled 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. Remove camshaft drive gear pulley fixing bolt (3),
then pulley (4).
2. Remove camshaft bearing cap fixing bolt (5),
camshaft bearing cap (6), then camshaft exhaust (7),
and intake side (8).
3. Remove tappet with shim (11).
4. Use the J±8062 valve spring compressor and
J±42898 valve spring compressor adapter to remove
the split collar (12), valve spring with upper seat (13)
and valve (14).
014RW042
5. Remove spark plug (1).
CAUTION: Do not remove the spark plugs when the
head and plugs are hot. Clean dirt and debris from
spark plug recess areas before removal.
Clean
Cylinder head
Carefully remove all varnish, soot and carbon from the
bare metal. Do not use surface conditioning disc on any
gasket sealing surface.
Inspection and Repair
1. Inspect 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
2. Inspect cylinder head for cracks, especially between
valve seats and in the exhaust ports.
3. Inspect cylinder head deck for corrosion, sand
particles in head and porosity.
CAUTION:

Do not attempt to weld the cylinder head. Replace
it.

Do not reuse cylinder head bolts.
4. Inspect cylinder head deck, common chamber and
exhaust manifold mating surfaces for flatness. These
surfaces may be reconditioned by milling. If the
surfaces are ªout of flatº with ªroundº by more than
specification, the surface should be ground to within
specifications. Replace the head if it requires
machining beyond the repairable limit.
Head surface and manifold surface
Standard: 0.05 mm (0.002 in) or less
Warpage limit: 0.2 mm (0.0079 in)
Maximum Repairable limit: 0.2 mm (0.0079 in)
Head height
Standard height : 133.2 mm (5.2441 in)
Warpage limit : 0.2 mm (0.0079 in)
Maximum Repairable limit : 133.0 mm (5.2362 in)
011RW019
5. Water jacket sealing plugs seating surfaces.

6D2±5
IGNITION SYSTEM (6VE1 3.5L)
Spark Plug
Removal
1. Remove spark plugs.
Inspection and Repair
The spark plug affects entire engine performance and
therefore its inspection is very important.

Check electrode and insulator for presence of cracks,
and replace if any.

Check electrode for wear, and replace if necessary.

Check gasket for damage, and replace if necessary.

Measure insulation resistance with an ohmmeter, and
replace if faulty.

Adjust spark plug gap to 1.0 mm ± 1.1 mm (0.0394 in ±
0.0433 in).
011RS011
NOTE:
± Do not adjust the spark plugs gap without new
spark plugs.
± Do not damage to tip of spark plugs.
± Do not cleaning the spark plugs. If require the
cleaning it due to heavy dirt, it is allowed only 20
seconds to be used spark plug cleaner.

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 performance.
Possible causes:

Too rich mixture

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

Improper heat value
Measuring Insulation Resistance

Measure insulation resistance using a 500 volt
megaohm meter.

Replace spark plugs if measured value is out of
standard.
Insulation resistance: 50 M
or more
011RS010
Installation
1. Spark plugs

Tighten spark plugs to the specified torque.
Torque: 18 N´m (13 lb ft)

6E±34
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Fuel quality is not a new issue for the automotive industry,
but its potential for turning on the MIL (ªCheck Engineº
lamp) with OBD II systems is new.
Fuel additives such as ªdry gasº and ªoctane enhancersº
may affect the performance of the fuel. If this results in an
incomplete combustion or a partial burn, it will show up as
a Misfire DTC P0300. The Reed Vapor Pressure of the
fuel can also create problems in the fuel system,
especially during the spring and fall months when severe
ambient temperature swings occur. A high Reed Vapor
Pressure could show up as a Fuel Trim DTC due to
excessive canister loading. High vapor pressures
generated in the fuel tank can also affect the Evaporative
Emission diagnostic as well.
Using fuel with the wrong octane rating for the vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using ªpremiumº gasoline will
improve the performance of the vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel's ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD II diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(ªCheck Engineº lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (ªCheck Engineº lamp) to turn on.
Aftermarket electronics, such as transceivers, stereos,
and anti-theft devices, may radiate EMI into the control
system if they are improperly installed. This may cause a
false sensor reading and turn on the MIL (ªCheck Engineº
lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (ªCheck Engineº
lamp).
Refueling
A new OBD II diagnostic was introduced in 1996 on some
vehicles. This diagnostic checks the integrity of the entire
evaporative emission system. If the vehicle is restarted
after refueling and the fuel cap is not secured correctly,
the on-board diagnostic system will sense this as a
system fault and turn on the MIL (ªCheck Engineº lamp)
with a DTC P0440.Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of operation
contributes to the fuel fouling of the spark plugs and will
turn on the MIL (ªCheck Engineº lamp) with a P0300
Misfire DTC.
Poor Vehicle Maintenance
The sensitivity of OBD II diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD II. Poor vehicle
maintenance can't be classified as a ªnon-vehicle faultº,
but with the sensitivity of OBD II diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD II system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Emissions Control Information Label
The engine compartment ªVehicle Emissions Control
Information Labelº contains important emission
specifications and setting procedures. In the upper left
corner is exhaust emission information. This identifies
the emission standard (Federal, California, or Canada) of
the engine, the displacement of the engine in liters, the
class of the vehicle, and the type of fuel metering system.
There is also an illustrated emission components and
vacuum hose schematic.
This label is located in the engine compartment of every
vehicle. If the label has been removed it should be
replaced. It can be ordered from Isuzu Dealership.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for pinches, cuts,
disconnections, and proper routing.

Inspect hoses that are difficult to see behind other
components.

6E±104
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
141. Ignition ªONº.
2. While the coil connectors are disconnected, touch
each coil connector's ignition feed terminal with a
grounded test light (the ignition feed wire is YEL
tracer).
Did the test light illuminate?
ÐGo to Step 16Go to Step 15
15Repair the open ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
16While the coil connectors are disconnected, touch
each connector's secondary ground terminal with a
test light to B +. (The ground wires are black.)
Did the test light illuminate at each coil connector?
ÐGo to Step 18Go to Step 17
17Repair the open secondary ground circuit.
Is the action complete?
ÐVerify repairÐ
181. Test the fuel for contamination.
2. If a problem is found, clean the fuel system and
correct the contaminated fuel condition as
necessary. Replace the fuel filter and replace any
injectors that are not delivering fuel (see Injector
Balance Test).
Was a problem found?
ÐVerify repairGo to Step 19
191. Remove any ignition coil and install a spark tester at
the spark plug end of the coil.
2. Observe the tester while the engine is cranking.
Was a crisp, blue spark observed? Only one or two
sparks followed by no result is considered the same as
ªNo Sparkº.
ÐGo to Step 21Go to Step 20
20Replace the ignition coil, and return to Step 19 to test
the remaining coils.
Is the action complete?
ÐVerify repairÐ
21Repeat Step 19 for each coil. Remove only one coil at a
time, and reinstall each coil on its spark plug after
testing, but do not refasten coils with screws at this
time.
After all coils have passed the spark test, does the
engine start?
Ð
Refasten all
coils with
their screws
Go to Step 22
221. Remove the spark plugs from all cylinders.
2. Visually inspect the spark plug electrodes.
3. Replace any spark plugs with loose or missing
electrodes or cracked insulators.
Did your inspection reveal any spark plugs exhibiting
excessive fouling?
Ð
Correct the
fouling
condition
Go to Step 23

6E±256
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0300 Engine Misfire Detected
Circuit Description
Misfire is monitored as a function of the combustion
quality (CQ) signals generated from the ION Sensing
Module. Combustion signals represent the degree of
combustion in each cylinder. Misfire is detected when the
combustion signal is below a predetermined value.
This DTC P0300 will determine if a multiple cylinder
misfire is occurring by monitoring the Combustion
Quality.
Conditions for Setting the DTC

None of the following DTCs occur: TP sensor, MAF
sensor, VSS, ECT sensor.

The engine speed is between 600 and 6250 RPM.

The system voltage is between 11 and 16 volts.

The engine temperature sensor (ECT) indicates an
engine temperature between ±7
C (20
F) and 110
C
(230
F).

Throttle angle is steady and throttle changes less than
2% per 125 milliseconds.
Action Taken When the DTC Sets

The PCM will ON the MIL after second trip with
detected the fault.

If the misfire is severe enough to cause possible
catalyst damage, the PCM will flash the MIL for as long
as the misfire remains at catalyst damaging levels.

The PCM will disable the TCC operation.

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

The PCM will turn the MIL ªOFFº on the third
consecutive trip cycle in which the diagnostic has been
run and the fault condition is no longer present.

A history DTC P0300 will clear after 40 consecutive
warm-up cycles occur without a fault.

DTC P0300 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
The Tech 2 display ªMisfire Cur. #1 through #6º can be
useful to determine whether the misfire is isolated to a
single cylinder.
Damaged or faulty ignition coil ± Check for cracks or
other damage.

Substitute a known good coil ± Swap the ignition coils
and retest. If the misfire follows the coil, replace the
ignition coil.
If the misfire is random, check for the following conditions:

System grounds ± Ensure all connections are clean
and properly tightened.

MAF ± A mass air flow (MAF) sensor output that
causes the PCM to sense a lower than normal air flow
will cause a lean condition.

Air induction system ± Air leaks into the induction
system which bypass the MAF sensor will cause a lean
condition. Check for disconnected or damaged
vacuum hoses, incorrectly installed or faulty PCV
valve, or for vacuum leaks at the throttle body, EGR
valve, and intake manifold mounting surfaces.

Fuel pressure ± Perform a fuel system pressure test.
A faulty fuel pump, plugged filter, or faulty fuel system
pressure regulator will contribute to a lean condition.

Injector(s) ± Perform an injector coil/balance test to
locate faulty injector(s) contributing to a lean or
flooding condition. In addition to the above test, check
the condition of the injector O-rings.

EGR ± Check for a leaking valve, adapter, or feed pipes
which will contribute to a lean condition or excessive
EGR flow.

Fuel quality ± Using fuel with the wrong octane rating
for the vehicle may cause driveability problems.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel's ability to turn into vapor in cold
temperatures deteriorates. This may affect the cold
driveability of the engine. The Reid Vapor Pressure of
the fuel can also create problems in the fuel system,
especially during the spring and fall when changes by
the refineries may not coincide with changes in the
weather.

Vehicle marshalling ± The transportation of new
vehicles from the assembly plant to the dealership can
involve as many as 60 key cycles within 2 to 3 miles of
driving. This type of operation contributes to the fuel
fouling of the spark plugs and will turn on the MIL with
a P0300 Misfire DTC.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.