cooling ISUZU AXIOM 2002 Service Service Manual

6E±520
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Fuel economy, as measured by an actual road test, is
noticeably lower than expected. Also, economy is
noticeably lower than it was on this vehicle at one time,
as previously shown by an actual road test.
(Non-standard tires will cause odometer readings to be
incorrect, and that may cause fuel economy to appear
poor when it is actually normal.)
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
ÐVerify repairGo to Step 3
3Was a visual/physical check performed?
ÐGo to Step 4
Go to Visual/
Physical
Check
4Check owner's driving habits.

Is the A/C ªONº full time (defroster mode ªONº)?

Are tires at the correct pressure?

Are excessively heavy loads being carried?

Is acceleration too much, too often?
Was a problem found?
ÐGo to Step 5Go to Step 6
5Review the items in Step 4 with the customer and
advise as necessary.
Is the action complete?
ÐSystem OKÐ
61. Visually/physically check: Vacuum hoses for splits,
kinks, and improper connections and routing as
shown on the ªVehicle Emission Control
Informationº label.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 7
71. Remove and check the air filter element for dirt or for
restrictions. Refer to
Air Intake System.
2. Replace the air filter element if necessary.
Was a repair required?
ÐVerify repairGo to Step 8
81. Remove spark plugs and check for wet plugs,
cracks, wear, improper gap, burned electrodes, or
heavy deposits. Refer to
Spark Plug Replacement.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 9
91. Check for low engine coolant level. Refer to Engine
Cooling
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10

6E±521
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom

 
StepNo Ye s Value(s) Action
101. Check for an incorrect or faulty engine thermostat.
Refer to
Engine Cooling.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
111. Check for low engine compression. Refer to Engine
Mechanical
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 12
121. Check the TCC operation. Refer to 4L30-E
Transmission Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 13
131. Check the exhaust system for possible restriction:

Inspect the exhaust system for damaged or
collapsed pipes.

Inspect the muffler for heat distress or possible
internal failure.

Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure. Refer to
Restricted
Exhaust System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 14
14Check for proper calibration of the speedometer.
Does the speed indicated on the speedometer closely
match the vehicle speed displayed on the Tech 2?
ÐGo to Step 16Go to Step 15
15Diagnose and repair an inaccurate speedometer
condition as necessary. Refer to
Vehicle Speed
Sensor
in Electrical Diagnosis.
Was a problem found?
ÐVerify repairÐ
161. Check the air intake system and the crankcase for
air leaks. Refer to
Air Intake System and
Crankcase Ventilation System.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 17
171. Review all diagnostic procedures within this table.
2. When all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All connections within a suspected circuit
and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 18
18Perform the procedure in Fuel System Pressure Test.
Was the fuel pressure normal?
Ð
Contact
Technical
Assistance
Verify repair

6E±522
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Excessive Exhaust Emissions or Odors Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Vehicle fails an emission test. Vehicle has excessive
ªrotten eggº smell. (Excessive odors do not necessarily
indicate excessive emissions.)
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
ÐGo to Step 13Go to Step 3
3Was a thorough visual/physical check performed?
ÐGo to Step 4
Go to Visual/
Physical
Check
41. Check for vacuum leaks. Check vacuum lines,
intake manifold, throttle body, etc.
2. If a problem is found, repair as necessary.
Were any vacuum leaks located?
ÐGo to Step 13Go to Step 5
51. Check the fuel cap for proper installation.
2. Secure the fuel cap if necessary.
Was the fuel cap installed properly?
ÐGo to Step 6Go to Step 13
61. Check the fuel pressure. Perform the procedure in
Fuel System Pressure Test.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 13Go to Step 7
71. Check for a faulty, plugged, or incorrectly installed
crankcase ventilation valve; also check the
crankcase ventilation system for plugging.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 13Go to Step 8
81. Check the injector connections.
2. If any of the injectors are connected to an incorrect
cylinder, correct as necessary.
Was a problem found?
ÐGo to Step 13Go to Step 9
91. Perform the ªInjector Coil/Balance Testº in Fuel
Metering System
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 13Go to Step 10
101. Refer to Engine Cooling for cooling system
diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 13Go to Step 11
111. Check EVAP canister for fuel loading. Refer to
Evaporative Emission Control System.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐGo to Step 13Go to Step 12

6E±536
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Symptoms Default Section(s)Initial Diagnosis
Surges and/or Chuggles1. OBD system check.
2. ETC system check.
3. Heated oxygen sensors.
4. Fuel system diagnosis.
5. Ignition system.Calibration ID/Service Bulletins,
Ignition System Check,
Generator Output, Exhaust
System Diagnosis, 4L30-E
System Test
Lack of Power, Sluggish or Spongy1. OBD system check.
2. ETC system check.
3. Fuel system diagnosis.
4. Ignition system.
5. EGR operation.
6. EGR system check.Refer to Exhaust System in
Engine Exhaust, TCC Operation,
Calibration ID/Service Bulletins
Detonation/Spark Knock1. OBD system check.
2. Transmission range switch.
3. EGR operation.
4. EGR system check.
5. TCC operation.
6. Fuel system diagnosis.
7. Ignition system.
8. ION sensing module check.TCC operation, Cooling System,
Ignition System Check,
Calibration ID/Service Bulletins
Rough, Unstable, or Incorrect Idle,
Stalling1. OBD system check.
2. ETC system check.
3. Fuel injector and fuel injector
balance test.
4. EVAP emission canister purge
valve check.
5. Ignition system.
6. EGR operation.MAP Output Check, Throttle
Linkage, EGR System Check,
A/C Clutch Control Circuit
Diagnosis, Crankcase Ventilation
System, Calibration ID/Service
Bulletins, Generator Output
Voltage (refer to
Chassis
Electrical
), Exhaust Diagnosis
Poor Fuel Economy1. OBD system check.
2. Careful visual/physical inspection.
3. Ignition system.
4. Cooling system.TCC Operation, Exhaust System
(refer to
Engine Exhaust)
Hesitation, Sag, Stumble1. OBD system check.
2. ETC system check.
3. TP.
4. MAP output check.
5. Fuel system diagnosis.
6. Fuel injector and fuel injector
balance test.
7. EVAP emission canister purge
valve.
8. Ignition system.EGR Operation, EGR System
Check, Generator Output
Voltage (refer to
Chassis
Electrical
), Calibration ID/Service
Bulletins, Ignition System Check
Cuts Out, Misses1. OBD system check.
2. Cylinder balance test.
3. ETC system check.Ignition System Check
Engine Cranks But Will Not Run1. OBD system check.Fuel System Electrical
Diagnosis, Fuel System
Diagnosis, Fuel Injector and Fuel
Injector Balance Test.

6E±537
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Symptoms Default Section(s)Initial Diagnosis
Excessive Exhaust Emissions or
Odors1. OBD system check.
2. Emission test.
3. Cooling system.
4. Fuel system diagnosis.
5. Fuel injector and fuel injector
balance test.
6. EVAP emission canister purge
valve.
7. Crankcase ventilation system.
8. Ignition system.
9. MAP output check.EGR System Check, Exhaust
Diagnosis, Calibration ID/Service
Bulletins
Dieseling, Run-On1. OBD system check.
2. Careful visual/physical inspection.
3. Fuel system diagnosis.Ð
Backfire1. OBD system check.
2. Ignition system.
3. Fuel system diagnosis.
4. Fuel injector and fuel injector
balance test.
5. EGR operation, EGR system
check.Exhaust System Diagnosis,
Intake Casting Flash, Ignition
System Check
Misfire1. OBD system check.
2. Ignition system.
3. Fuel system diagnosis.
4. Fuel injector and fuel injector
balance test.Vibrations, Transmission,
Driveshaft and Axle
Catalyst Monitor1. OBD system check.
2. Careful visual/physical inspection.
3. Heated oxygen sensors.Exhaust System
Fuel Trim1. OBD system check.
2. Careful visual/physical inspection.
3. Fuel system diagnosis.
4. Heated oxygen sensors, MAF
sensors.Exhaust System Intake Air
System
Evaporative Emissions1. OBD system check.
2. Careful visual/physical inspection.
3. Fuel system diagnosis.Ð
Heated Oxygen Sensors1. OBD system check.
2. Careful visual/physical inspection.Exhaust System

6E±538
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
On Vehicle
Service Crankshaft Position
(CKP) Sensor
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the electrical connector to the CKP
sensor.
3. Remove one bolt and the CKP sensor from the right
side of the engine block, just behind the mount.
NOTE: Use caution to avoid any hot oil that might drip
out.
TS22909
Inspection Procedure
1. Inspect the sensor O-ring for cracks or leaks.
2. Replace the O-ring if it is worn or damaged.
3. Lubricate the new O-ring with engine oil.
4. Install the lubricated O-ring.
Installation Procedure
1. Install the CKP sensor in the engine block.
2. Install the CKP sensor mounting bolt.
Tighten

Tighten the mounting bolt to 9 N´m (78 lb in.).
TS22909
3. Connect the electrical connector to the CKP sensor.
4. Connect the negative battery cable.
Engine Coolant Temperature
(ECT) Sensor
Removal Procedure
NOTE: Care must be taken when handling the engine
coolant temperature (ECT) sensor. Damage to the ECT
sensor will affect proper operation of the fuel injection
system.
1. Disconnect the negative battery cable.
2. Drain the radiator coolant. Refer to
Draining and
Refilling Cooling System
in Engine Cooling section.
3. Disconnect the electrical connector.
014RY00001

6E±539
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
4. Remove the ECT sensor from the coolant crossover.
014RY00002
Installation Procedure
1. Apply sealer or the equivalent to the threads of the
ECT sensor.
2. Install the ECT sensor in the coolant crossover.
Tighten

Tighten the ECT sensor to 30 N´m (22 lb ft.).
014RY00002
3. Connect the electrical connector.
014RY00003
4. Fill the radiator with coolant. Refer to Draining and
Refilling Cooling System
in Engine Cooling section.
5. Connect the negative battery cable.
Heated Oxygen Sensor (HO2S)
Removal Procedure
1. Disconnect the negative battery cable.
2. Locate the four oxygen sensors.
060RW008

6E±558
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
5. Connect the connectors to manifold absolute
pressure sensor, solenoid valve, electric vacuum
sensing valve.
6. Connect the throttle position sensor electrical
connector to throttle body.
7. Install the engine cover.
8. Connect the negative battery cable.
9. Crank the engine until it starts. Cranking the engine
may take longer than usual due to trapped air in the
fuel rail and in the injectors.
Fuel Tank
Removal Procedure
Refer to Fuel Tank In Fuel Pump Relay
014RW134
Throttle Body (TB)
Removal Procedure
1. Disconnect the negative battery cable.
2. Drain the cooling system. Refer to
Cooling System
section.
3. Disconnect the electrical connectors:

Throttle position (TP) sensor.

Intake air temperature (IAT) sensor. Refer to
Intake
Air Temperature Sensor
section.
060RY00014
4. Disconnect the vacuum hose below the air horn.
5. Remove the intake air duct clamp.
6. Disconnect the intake air duct.
7. Disconnect the coolant lines from the throttle body.
8. Remove the bolts from the common chamber.
9. Remove the throttle body from the common chamber.
10. Remove the gasket from the common chamber.
025RY00004
11. Remove the TP sensor. Refer to Throttle Position
(TP) Sensor
section.

6E±559
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Inspection Procedure
NOTE: Do not use solvent of any type when you clean the
gasket surfaces on the intake manifold and the throttle
body assembly. The gasket surfaces and the throttle
body assembly may be damaged as a result.

If the throttle body gasket needs to be replaced,
remove any gasket material that may be stuck to the
mating surfaces of the manifold.

Do not leave any scratches in the aluminum casting.
Installation Procedure
1. Install the TP sensor. Refer to Throttle Position (TP)
Sensor
section.
2. Install the gasket on the common chamber.
3. Install the throttle body on the common chamber.
4. Secure the gasket and the throttle body with the four
bolts.

The vacuum lines must be properly routed under
the throttle body before tightening the mounting
bolts.
Tighten

Tighten the throttle body mounting bolts to 10
N´m (87 lb in).
025RY00004
5. Install the coolant lines.
6. Connect all the vacuum lines.
7. Install the intake air duct.
8. Tighten the intake air duct clamp.9. Connect all the electrical connectors:

Throttle position (TP) sensor.

Intake air temperature (IAT) sensor. Refer to
Intake
Air Temperature Sensor
section.
060RY00020
10. Install the accelerator cable assembly. Refer to
Accelerator Cable in Engine Speed Control System
section.
11. Fill the cooling system. Refer to
Cooling System
section.
12. Install the negative battery cable.

6E±582
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Crankshaft position (CKP) sensor.
Spark Plug
Although worn or dirty spark plugs may give satisfactory
operation at idling speed, they frequency fail at higher
engine speeds. Faulty spark plugs may cause poor fuel
economy, power loss, loss of speed, hard starting and
generally poor engine performance. Follow the
scheduled maintenance service recommendations to
ensure satisfactory spark plug performance. Refer to
Maintenance and Lubrication section.
Normal spark plug operation will result in brown to
grayish-tan deposits appearing on the insulator portion of
the spark plug. A small amount of red-brown, yellow, and
white powdery material may also be present on the
insulator tip around the center electrode. These deposits
are normal combustion by-products of fuels and
lubricating oils with additives. Some electrode wear will
also occur. Engines which are not running properly are
often referred to as ªmisfiring.º This means the ignition
spark is not igniting the air/fuel mixture at the proper time.
While other ignition and fuel system causes must also be
considered, possible causes include ignition system
conditions which allow the spark voltage to reach ground
in some other manner than by jumping across the air gap
at the tip of the spark plug, leaving the air/fuel mixture
unburned. Refer to
DTC P0300. Misfiring may also occur
when the tip of the spark plug becomes overheated and
ignites the mixture before the spark jumps. This is
referred to as ªpre-ignition.º
Spark plugs may also misfire due to fouling, excessive
gap, or a cracked or broken insulator. If misfiring occurs
before the recommended replacement interval, locate
and correct the cause.
Carbon fouling of the spark plug is indicated by dry, black
carbon (soot) deposits on the portion of the spark plug in
the cylinder. Excessive idling and slow speeds under
light engine loads can keep the spark plug temperatures
so low that these deposits are not burned off. Very rich
fuel mixtures or poor ignition system output may also be
the cause. Refer to DTC P0172.
Oil fouling of the spark plug is indicated by wet oily
deposits on the portion of the spark plug in the cylinder,
usually with little electrode wear. This may be caused by
oil during break-in of new or newly overhauled engines.
Deposit fouling of the spark plug occurs when the normal
red-brown, yellow or white deposits of combustion by
products become sufficient to cause misfiring. In some
cases, these deposits may melt and form a shiny glaze on
the insulator around the center electrode. If the fouling is
found in only one or two cylinders, valve stem clearances
or intake valve seals may be allowing excess lubricating
oil to enter the cylinder, particularly if the deposits are
heavier on the side of the spark plug facing the intake
valve.
TS23995Excessive gap means that the air space between the
center and the side electrodes at the bottom of the spark
plug is too wide for consistent firing. This may be due to
improper gap adjustment or to excessive wear of the
electrode during use. A spark plug gap that is too small
may cause an unstable idle condition. Excessive gap
wear can be an indication of continuous operation at high
speeds or with engine loads, causing the spark to run too
hot. Another possible cause is an excessively lean fuel
mixture.
TS23992Low or high spark plug installation torque or improper
seating can result in the spark plug running too hot and
can cause excessive center electrode wear. The plug
and the cylinder head seats must be in good contact for
proper heat transfer and spark plug cooling. Dirty or
damaged threads in the head or on the spark plug can
keep it from seating even though the proper torque is
applied. Once spark plugs are properly seated, tighten
them to the torque shown in the Specifications Table. Low
torque may result in poor contact of the seats due to a
loose spark plug. Overtightening may cause the spark
plug shell to be stretched and will result in poor contact