Fuel System – V6 Page 6C – 34
Fuel Tank Lines
Figure 6C – 38
Legend
1 Fuel Feed Line
2 Fuel Return Line
3 Fuel Vapour emission port
4 Fuel Pump and Sender Assembly
5 Connector; Fuel Pump and Sender 6 Fuel Lines
7 Retainer Ring (Fuel Pump Lock)
8 “O” Ring Seal
9 Fuel Tank Assembly
10 Fuel Vapour Vent Line
Reinstall
Ensure the plastic fuel line clips are in good
condition before proceeding. If not, replace
the defective clips.
Reinstallation of the stone guard and fuel lines is the reverse of the removal procedure, noting the following:
1 Tighten the Fuel line securing nut to the correct torque specification, refer to Figure 6C – 39.
Fuel line securing nut
torque specification .........................................8 – 12 Nm
2 Tighten the stone guard securing bolts to the correct torque specification. Stone guard securing bolt
torque specification .....................................5.0 – 7.0 Nm
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ISUZU KB P190 2007
Engine Management – V6 – General Information Page 6C1-1–33
The knock sensor is tuned to detect the frequency of the
vibration created by combustion knock. The vibration is
transferred to the knock sensor through the cylinder
block (1).
Inside the sensor is a mass (2) that is excited by this
vibration, and the mass exerts a compressive force onto a
piezo-ceramic element (3). The compressive force causes a
charge transfer inside the element, so that an AC voltage
appears across the two outer faces (4) of the element. The
amount of the AC voltage produced is proportional to the
amount of knock.
Figure 6C1-1 – 42
4.18 Mass Air Flow Sensor
Air Intake System
The air intake system draws outside air through an air
cleaner assembly (1). The air is then routed through a mass
air flow (MAF) sensor (2) and into the throttle body and
intake manifold. The air is then directed into the intake
manifold runners, through the cylinder heads and into the
cylinders.
An arrow marked on the body of the MAF sensor indicates
correct air flow direction. The arrow must point toward the
engine.
Figure 6C1-1 – 43
Mass Air Flow Sensor
A hot film type mass air flow (MAF) sensor is used which
measures the air mass inducted into the engine, regardless
of the engine’s operating state. The MAF precisely
measures a portion of the total airflow and takes into
account the pulsation and reverse flows generated by the
engine’s inlet and exhaust valves.
Changes in intake air temperature have no effect on
measuring accuracy.
Figure 6C1-1 – 44
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Engine Management – V6 – Diagnostics Page 6C1-2–27
5.5 Cuts Out, Misses
Description
Steady pulsation or jerking that is usually more severe as the engine load increases. This condition is not normally felt
greater than 1500 rpm or 48 km/h. The exhaust has a steady spitting sound at idle or low speed.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
• Check for intake manifold vacuum leak.
Sensor / System
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard
activity. Check for items that cause spark retard activity. Refer to 7.19 DTC
P0327, P0328, P0332 or P0333.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check for fault conditions that cause an engine to run rich or to run lean.
Ignition System
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil grounds.
Engine Mechanical Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –V6.
• low compression, and
• worn valve train components.
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ISUZU KB P190 2007
Engine Management – V6 – Diagnostics Page 6C1-2–30
Checks Actions
Ignition System
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Mechanical
• Check for excessive oil in combustion chamber. Refer to 6A1 Engine Mechanical
– V6.
• Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –
V6.
• low compression, and
• worn valve train components.
When all diagnosis and repairs are completed, check the system for correct operation.
5.9 Hesitation, Sag and Stumble
Description
Momentary lack of response or hesitation as the accelerator is depressed. This condition is usually more severe when
first trying to make the vehicle move from a standing start but can occur at any vehicle speed.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
Sensor / System
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
• Inspect the accelerator pedal position (APP) sensor harness connector for correct
connection. Poor connection of this connector will not set a DTC.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C Fuel System – V6.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check for fault conditions that cause an engine to run rich or to run lean.
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ISUZU KB P190 2007
Engine Management – V6 – Diagnostics Page 6C1-2–31
Checks Actions
Ignition System
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Cooling System Check the engine thermostat for correct operation and heat range. Refer to 6B1 Engine
Cooling – V6.
Additional Checks • Check the generator output voltage. Refer to 6D1-1 Charging System – V6.
When all diagnosis and repairs are completed, check the system for correct operation.
5.10 Lack of Power, Sluggishness or
Sponginess
Description
The engine delivers less than normal power. There is little or no increase in vehicle speed when the accelerator pedal is
partially depressed.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
Sensor / System
• Use Tech 2 to monitor the knock sensor system for excessive spark retard
activity. Check for items that cause spark retard activity.
• Inspect the accelerator pedal position (APP) sensor harness connector for correct
connection. Poor connection of this connector will not set a DTC.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check for fault conditions that can cause the engine to run rich or run lean.
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Engine Management – V6 – Diagnostics Page 6C1-2–32
Checks Actions
Ignition System
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs, refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Mechanical
• Check for the following engine mechanical fault condition. Refer to 6A1 Engine
Mechanical – V6.
• low engine compression, and
• worn valve train components.
Additional Checks
• Check the exhaust system for possible restrictions. Refer to 6F Exhaust System –
V6.
• Test for other TCM related faults that may cause the transmission to operate in
the default mode.
• Check for transmission mechanical faults that may produce similar symptoms
such as slipping clutch.
When all diagnosis and repairs are completed, check the system for correct operation.
5.11 Poor Fuel Economy
Description
As confirmed by an actual road test, the fuel economy as compared to the previous fuel consumption of the same
vehicle is noticeably lower.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
• Check for correct tyre pressure. Refer to the Owners Manual.
• Check the recent driving conditions are the same compared to the previous when
the fuel consumption is normal. The following are list of driving conditions that
may affect fuel consumption:
− vehicle load,
− acceleration rate,
− A/C or other electrical equipment use, and
− vehicle used for towing.
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Engine Management – V6 – Diagnostics Page 6C1-2–34
Checks Actions
Additional Checks
• Check the exhaust system for possible restrictions. Refer to 6F Exhaust System –
V6.
• Electromagnetic interference (EMI) on the crankshaft position (CKP) sensor can
cause an engine misfire condition.
Using Tech 2, monitor the engine speed parameter. A sudden increase in the engine speed parameters without moving the throttle position indicates that an
Electromagnetic Interference fault may be present.
W iring harness routing which may be positioned very close to a high voltage or high current device such as the following may induce EMI:
• secondary ignition components, and
• motors and generators.
• Check the torque converter clutch (TCC) operation. A TCC that applies too soon
can cause engine detonation, which will trigger spark retard activity. Refer to 7C2
Automatic Transmission – 4L60E – Electrical Diagnosis.
• Test for other TCM related faults that may cause the transmission to operate in
the default mode. Refer to 7C2 Automatic Transmission – 4L60E – Electrical
Diagnosis.
• Check for transmission mechanical faults such as slipping clutch. Refer to 7C3
Automatic Transmission – 4L60E – Hydraulic and Mechanical Diagnosis.
• Check the brake system including the parking brake for sticking or incorrect
operation.
When all diagnosis and repairs are completed, check the system for correct operation.
5.12 Rough, Unstable, Incorrect Idle or
Stalling
Description
Engine idle speed fluctuates causing the engine to run unevenly. If the engine idle speed drops too low, the engine may
stall.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
Sensor / System
• Check the throttle actuator control (TAC) system. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
• Check the air intake system and crankcase for air leaks. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
• Check the PCV System for correct operation. Refer to 6A1 Engine Mechanical –
V6.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard
activity. Check for items that cause spark retard activity.
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s sensor should respond quickly to different throttle positions.
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ISUZU KB P190 2007
Engine Management – V6 – Diagnostics Page 6C1-2–48
Additional Information
• Use the J 35616-B Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a
component harness connector.
• Inspect the ignition coils for aftermarket devices. An aftermarket device connected to the ignition coil circuits, may
cause a condition with the ignition coils.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
4 The ignition coils for each bank are fused separately. If a fuse opens or the ignition 1 voltage circuit opens between the fuse and the splice, all the ignition coils for one bank of the engine would be inoperative. If the ground
circuit opens at the engine block, the ignition coils would be inoperative for one bank of the engine.
5 This step tests for an open or a high resistance in the ignition 1 voltage circuit of the ignition coil. If the DMM does not display near battery voltage there is an open or a high resistance in the circuit.
6 This step determines if the ground circuit is open. If the circuit is open, the ignition coils would be inoperative for one bank of the engine.
7 This step determines if the ignition 1 voltage circuit is shorted to ground. If the fuse is open, the ignition coils would be inoperative for one bank of the engine.
Diagnostic Table
Step Action Value(s) Yes No
1
Has the Diagnostic System Check been performed? —
Go to Step 2 Refer to
4.4 Diagnostic System Check
2 W ere you sent here from DTC P0300 or P0301-P0306? —
Go to Step 3 Go to DTC P0300 or
DTC P0301 – P0306
3 1 Start the engine.
2 Allow the engine to reach operating temperature.
3 Operate the engine at 2,000 rpm.
4 Monitor all of the Misfire Current Counters with a scan tool. There are a total of 6 counters,
1 counter per cylinder.
Are any of the Misfire Current Counters incrementing? —
Go to Step 4 Go to
5.2 Intermittent Fault Conditions
4 Are all the misfire counters incrementing for one bank
of the engine? —
Go to Step 7 Go to Step 5
5 1 Ignition OFF.
2 Disconnect the appropriate ignition coil.
3 Ignition ON, engine OFF.
4 Connect a test lamp between the battery voltage circuit of the ignition coil and a good ground.
5 Measure the voltage between the probe of the test lamp and a good ground with a DMM. Refer
to 8A Electrical - Body and Chassis for the
procedure to measure voltage drop.
Is the voltage at the specified value? B+
Go to Step 6 Go to Step 9
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