2004 ISUZU TF SERIES engine

6E–262 ENGINE DRIVEABILITY AND EMISSIONS
BACKFIRE SYMPTOM
DEFINITIONS: Fuel ignites in the intake manifold, or in the ex haust system, making a loud popping noise.
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. 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?—Verify repair Go to Step 3
3 Was a visual/physical check performed?
—Go to Step 4Go to Visual /
physical Check.
4 Check for proper ignition voltage output with the spark
tester.
Was a problem found?—Verify repair Go to Step 5
5 1. Remove the spark plugs and check for gas or oil
fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.
2. If spark plugs are fouled, the cause of fouling must
be determined before replacing the spark plugs.
Was a problem found?—Verify repair Go to Step 6
6 Visually/physically inspect all spark plug high-tension
cables. Check for the following conditions:
Verify that the resistance of all spark plug high-
tension cables are less than the specified value.
Verify that the all spark plug high-tension cables are
correctly fitted to eliminate cross-fitting.
Verify that the all spark plug high-tension cables are
not arcing to ground.
Spraying the spark plug high-tension cables with a
light mist of water may help locate an intermittent
problem.
Was a problem found?#1 cyl. 4.4k

#2 cyl. 3.6k

#3 cyl. 3.1k

#4 cyl. 2.8k
Verify repair Go to Step 7
7 Check the fuel pressure. Refer to 6E-108 page “Fuel
System Diagnosis” .
Was a problem found?—Verify repair Go to Step 8
8 Check for an intermittent ignition system malfunction:
Intermittent CKP 58X signal
Intermittent ignition feed circuit or sensor ground
circuit to the crankshaft position sensor.
Was a problem found?—Verify repair Go to Step 9
9 Refer to 6E-108 page
Fuel System Diagnosis to
determine if there is a problem with fuel delivery.
Was a problem found?—Verify repair Go to Step 10

ENGINE DRIVEABILITY AND EMISSIONS 6E–263
10 Check for the following engine mechanical problems
(refer to Engine Mechanical):
Low compression
Leaking cylinder head gaskets
Worn camshaft
Sticking or leaking valves
Valve timing
Broken valve springs
Camshaft drive belt slipped or stripped
Was a problem found?—Verify repair Go to Step 11
11 Check leakage at exhaust system.
Check the intake and ex haust manifold for casting
flash. Refer to Engine Mechanical.
Was a problem found?—Verify repair Go to Step 12
12 1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
followi ng:
Visual/physical inspection
Te c h 2 d a t a
All electrical connections within a suspected
circuit and/or system
Was a problem found?—Verify repair Go to Step 13
13 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 14
14 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Veri fy repai r— Step Action Value(s) Yes No

6E–264 ENGINE DRIVEABILITY AND EMISSIONS
ON-VEHICLE SERVICE PROCEDURE
ENGINE CONTROL MODULE (ECM)
Location
On the intake manifold.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the two connectors from the ECM.
3. Remove four bolts.
4. Remove the ECM from bracket.
Installation Procedure
1. Put on the ECM to the bracket.
2. Tighten the ECM by four bolts with specified
tightening torque.
Tightening torque
Bolts: 8.0 - 12.0 N·m (0.8 - 1.2 kgf·m)
3. Connect the two connectors to the ECM.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
CRANKSHAFT POSITION (CKP) SENSOR
Location
Left-hand side of the cylinder block. (Back of the A/C
compressor)
Removal Procedure
1. Disconnect the negative battery cable.
2. Remove the drive belt. Refer to Engine Mechanical
Section.
3. Remove the A/C compressor from engine. Refer to
Engine Mechanical Section.
4. Disconnect connector from the CKP sensor.
5. Loosen a bolt and remove the CKP sensor from the
cylinder block.
NOTE: Use caution to avoid any hot oil that might drip
out.
Installation Procedure
1. Install the CKP sensor to the cylinder block.
2. Tighten CKP sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolt: 6N·m (0.6kgf·m)
3. Reinstall the A/C compressor to the engine.
4. Reinstall the accessory drive belt.
5. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.

ENGINE DRIVEABILITY AND EMISSIONS 6E–265
ENGINE COOLANT TEMPERATURE (ECT)
SENSOR
Location
Installed to the thermostat housing.
Removal Procedure
1. Disconnect the negative battery cable.
2. Drain enough engine coolant so that the coolant
level will be below the ECT sensor.
3. Disconnect connector from the ECT sensor.
4. Loosen and remove the ECT sensor from the
thermostat housing.
NOTE: Cool down the engine before above procedures
are carried out.
Installation Procedure
1. Apply sealer to threads of screw at the ECT sensor.
2. Tighten the ECT sensor with specified tightening
torque.
Tightening Torque
Bolt: 13N·m (1.3kgf·m)
3. Connect a ECT sensor connector to the ECT
sensor.
4. Fill the engine coolant.
5. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify no engine coolant leaking from the sensor
threads after replacement.
INTAKE AIR TEMPERATURE (IAT) SENSOR
Location
Installed to the intake duct housing.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect a IAT sensor connector from the IAT
sensor.
3. Remove the IAT sensor from the intake duct.
Installation Procedure
1. Install the IAT sensor into intake air duct.
2. Connect a IAT sensor connector to the IAT sensor.
3. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.

6E–266 ENGINE DRIVEABILITY AND EMISSIONS
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR
Location
Installed on the intake manifold.
Removal Procedure
1. Disconenct the negative battery cable.
2. Disconnect a MAP sensor connector from the MAP
sensor.
3. Loosen a bolt and remove the MAP sensor from the
intake manifold.
4. Remove the MAP sensor from the bracket.
Installation Procedure
1. Tighten the MAP sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolt: 8N·m (0.8kgf·m)
2. Connect a MAP sensor connector to the MAP
sensor.
3. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
THROTTLE POSITION SENSOR (TPS)
Location
Installed on the throttle body.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the TPS connector.
3. Loosen two screws and remove TPS from the
throttle body.
Installation Procedure
1. Temporary tighten the TPS by two screws.
2. Connect a TPS connectors to the TPS.
3. Connect the Tech2 to the vehicle.
4. Connect the negative battery cable.
5. Select "Data Display" with the Tech2.
6. Check the throttle position data and adjust the TPS
position.
7. Tighten two screws.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.

ENGINE DRIVEABILITY AND EMISSIONS 6E–267
IDLE AIR CONTROL (IAC) VALVE
Location
Installed on the throttle body.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the IAC valve connector.
3. Loosen two screws and remove IAC valve from the
throttle body.
Cleaning and Inspection
1. Clean the IAC valve O-ring sealing surface, pintle
valve seat and air passage.
2. Use carburetor cleaner and a parts cleaning brush
to remove carbon deposit.
Do not use a cleaner that contain methyl ethyl
ketone. This is an extremely strong solvent and not
necessary for this type of deposit.
3. Shiny spots on the pintle are normal and do not
indicate misalignment or a bent pintle shaft.
4. Inspect the IAC valve O-ring for cuts, cracks or
distortion.
Measurement
Clean the IAC valve O-ring sealing surface, pintle
valve seat and air passage.
Use carburetor cleaner and a parts cleaning brush to
remove carbon deposit. Do not use a cleaner that
contain methyl ethyl ketone. This is an ex tremely
strong solvent and not necessary for this type of
deposit.
Shiny spots on the pintle are normal and do not
indicate misalignment or a bent pintle shaft.
Inspect the IAC valve O-ring for cuts, cracks or
distortion. Replace the O-ring if damaged.Installation Procedure
1. Tighten the IAC valve by two screws.
2. Connect a IAC valve connector to the MAP sensor.
3. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.

6E–268 ENGINE DRIVEABILITY AND EMISSIONS
KNOCK SENSOR
Location
Right-hand side of the cylinder block.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the knock sensor connector.
3. Loosen a bolt and remove knock sensor from the
cylinder block.
Installation Procedure
1. Tighten the knock sensor by a bolt with specified
tightening torque.
Tightening Torque
Bolt: 20N·m (2.0kgf·m)
2. Connect a knock sensor connector to the knock
sensor.
3. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
POWER STEERING PRESSURE (PSP)
SWITCH
Location
Installed on the power steering pump assembly.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the power steering pressure switch
connector.
3. Loosen and remove the power steering pressure
switch from the power steering pump.
Installation Procedure
1. Install the power steering pressure switch to the
power steering pump.
2. Tighten the power steering pressure switch.
3. Connect a connector to the power steering pressure
switch.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify no power steering fluid leaking from the sensor
threads after replacement.

ENGINE DRIVEABILITY AND EMISSIONS 6E–269
HEATED OXYGEN SENSOR (HO2S)
Location
Installed on the ex haust pipe.
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the O
2 sensor connector.
3. Loosen and remove the O
2 sensor from the ex haust
pipe.
Inspection
Inspect the louvered end of the sensor for grease, dirt,
ex cessive carbon build up or other contamination.
Installation Procedure
1. Install the O
2 sensor to the ex haust pipe.
2. Tighten the O
2 sensor with specified tightening
torque.
Tightening Torque
Bolt: 42N·m (4.3kgf·m)
3. Connect a O
2 sensor connector to the O2 sensor.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify no exhaust gas leaking from the sensor threads
after replacement.
EVAP CANISTER PURGE VALVE
SOLENOID
Location
On the intake manifold.
Removal Procedure
1. Disconenct the negative battery cable.
2. Disconnect a purge solenoid connector from the
purge solenoid.
3. Disconnect two hoses from the purge solenoid
valve.
4. Slide from the bracket and remove the purge
solenoid.
Installation Procedure
1. Insert EVAP purge solenoid valve onto the bracket.
2. Connect two hoses to the purge solenoid valve.
3. Connect a purge solenoid connector to the purge
solenoid.
4. Connect the negative battery cable.
NOTE: Verify any DTCs (diagnosis Trouble Code) are
not stored after replacement.
Verify proper connection of two hoses.