fuel ISUZU TF SERIES 2004 Workshop Manual

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-363
Step Action Value (s) Yes No
14
Check the EVAP purge solenoid valve operation.
Is the valve operated normally?
- Verify repair &
Go to Step 17 Verify repair &
Go to Step 15
15
Check the exhaust system for a possible restriction:

Damaged or collapsed pipes.

Internal catalytic converter failure.
Was a problem found?
- Verify repair &
Go to Step 17 Go to Step 16
16
1. Remove excessive carbon buildup with a top
engine cleaner. Refer to the instructions on the top
engine cleaner can.
2. Perform the exhaust emission test.
Does the vehicle pass the test?
- System OK Go to Step 18
17
Perform the exhaust emission test.
Does the vehicle pass the test?
- System OK Go to Step 18
18
Check the fuel control Heated Oxygen Sensor
(HO2S). When monitored on the Tech 2, the HO2S
should respond quickly to different throttle positions. If
it doesn't check for silicon or other contaminates from
fuel or use of improper sealant. The sensors may have
a white powdery coating. Silicon contamination sends
a rich exhaust signal which causes the ECM to
command and excessively lean air/fuel mixture.
Was a problem found?
- Verify repair Go to Step 19
19
Monitor "B1S1 (Bank 1 Sensor 1) Status" and "B2S1
(Bank 2 Sensor 1) Status" on the Tech 2.
Is the "B1S1 (Bank 1 Sensor 1) Status" or "B2S1
(Bank 2 Sensor 1) Status" in the rich condition?
- Go to Step 20 Go to Step 21
20
Check items that can cause the engine to run rich.
Refer to DTC P0172 "O2 Sensor System Too Rich
(Bank 1)" or DTC P0175 "O2 Sensor System Too Rich
(Bank 2)".
Was a problem found?
- Verify repair Go to Step 22
21
Check items that can cause the engine to run lean.
Refer to DTC P0171 "O2 Sensor System Too Lean
(Bank 1)" or DTC P0174 "O2 Sensor System Tool
Lean (Bank 2)".
Was a problem found?
- Verify repair Go to Step 22
22
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.
Was a problem found?
- Verify repair Go to Step 23

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-365
DIESELING, RUN-ON SYMPTOM
DEFINITIONS: Engine continues to run after key is
turned OFF, but runs very rough. If engine runs
smoothly, check the ignition switch and adjustment.



Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (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 visually/physical check performed?
- Go to Step 4 Go to Visual /
physical Check.
4
Check for a short between voltage circuit and the
ignition feed circuit.
Was a problem found?
- Verify repair Go to Step 5
5
Check the fuel leaking from injector. Perform the
Injector Coil/Balance Test.
Refer to 6E-106 page.
Was a problem found?
- Verify repair Go to Step 6
6
1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection.

Tech 2 data.

All electrical connections within a suspected circuit
and/or system.
Was a problem found?
- Verify repair Go to Step 7
7
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 8
8
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.
- Verify repair -

6E-366 3.5L ENGINE DRIVEABILITY AND EMISSIONS
BACKFIRE SYMPTOM
DEFINITIONS: Fuel ignites in the intake manifold, or in
the exhaust system, making a loud popping noise.



Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (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 visually/physical check performed?
- Go to Step 4 Go 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
Check the ignition coils for cracks or carbon tracking.
If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 6
6
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 7
7
Check the fuel pressure. Refer to Fuel System
Pressure Test.
Was a problem found?
- Verify repair Go to Step 8
8
Refer to 6E-116 page Fuel System Diagnosis to
determine if there is a problem with fuel delivery.
Was a problem found?
- Verify repair Go to Step 9
9
Check the CKP sensor signal, shield wire, or
installation condition. Refer to DTC P0336 "Crankshaft
Position Sensor Circuit Range/Performance" and DTC
P0337 "Crankshaft Position Sensor Circuit No Signal".
Was a problem found?
- Verify repair Go to Step 10

6E-374 3.5L ENGINE DRIVEABILITY AND EMISSIONS
FUEL PRESSURE RELIEF
Caution:
To reduce the risk of the fire and personal injury, it
is necessary to relive the fuel system pressure
before servicing the fuel system components.
Caution:
After relieving the fuel system pressure, a small
amount of fuel may be released when servicing fuel
lines or connections. Reduce the chance o
f
personal injury by covering the fuel line fitting with
a short towel before disconnecting the fittings. The
towel will absorb any fuel that may leak out. When
the disconnect is completed, place the towel in an
approved container.

1. Remove the fuel filler cap.
2. Remove the fuel pump relay.
3. Start the engine and allow it to stall.
4. Crank the engine for about 30 seconds.
5. Disconnect the negative battery cable.



FUEL RAIL ASSEMBLY

Removal Procedure
NOTE:
 Do not attempt to remove the fuel inlet fitting on
the fuel rail. It is staked in place. Removing the
fuel inlet fitting will result in damage to the fuel
rail or the internal O-ring seal.
 Use care when removing the fuel rail assembly in
order to prevent damage to the injector electrical
connector terminals and the injector spray tips.
 Fittings should be capped and holes plugged
during servicing to prevent dirt and othe
r
contaminants from entering open lines and
passages.
Important: Before removal, the fuel rail assembly may
be cleaned with a spray type engine cleaner. Follow the
spray package instructions. Do not immerse the fuel
rails in liquid cleaning solvent.
1. Depressurize the fuel system. Refer to Fuel
Pressure Relief Procedure in this Section.
2. Disconnect the negative battery cable.
3. Remove the engine cover.
4. Disconnect the accelerator pedal cable from throttle
body and cable bracket.

5. Disconnect the connectors from, solenoid valve,
sensing valve.
6. Disconnect the vacuum hose on canister solenoid
and positive crankcase ventilation hose.
7. Remove the common chamber Refer to the
common chamber in Engine Mechanical.
1. Lift up carefully on the fuel injectors. Do no
t
separate the fuel injectors from the fuel rail.
2. If an injector becomes separated from the fuel
rail, the infector O-ring seals and the retaine
r
clip must be replaced.
3. Drain residual fuel into an approved container.




060RW044
8. If removal of the fuel pressure regulator is
necessary, refer to Fuel Pressure Regulator.
9. If removal of the fuel injectors is necessary, refer to
Fuel Injectors.

Installation Procedure
1. If the fuel injectors were removed, install them.
Refer to Fuel Injectors.
2. If the fuel pressure regulator was removed, install
it. Refer to Fuel Pressure Regulator.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-375
3. Install the common chamber. Refer to common
chamber in engine Mechanical.




060RW044
4. Connect the vacuum hose on Canister Solenoid
and positive crankcase ventilation hose.
5. Connect the connectors to, solenoid valve.
6. Connect the accelerator pedal cable to throttle
body and cable bracket.
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 INJECTORS

Removal Procedure
NOTE: If the fuel injectors are leaking, the engine oil
may be contaminated with fuel. Check the oil fo
r
signs of contamination and change the oil and the
filter if necessary.
NOTE: Use care in removing the fuel injectors in
order to prevent damage to the fuel injecto
r
electrical connector pins or the fuel injector
nozzles. The fuel injector is an electrical component
and should not be immersed in any type of cleane
r
as this may damage the fuel injector.
Important: Fuel injectors are serviced as a complete
assembly only.
1. Disconnect the negative battery cable.
2. Remove the upper intake manifold. Refer to
Common Chamber in Engine Mechanical..
3. Remove the fuel rail. Refer to Fuel Rail.




060RW044

6E-376 3.5L ENGINE DRIVEABILITY AND EMISSIONS
4. Remove the injector retainer clip.






F06RW017
5. Remove the fuel injector assembly.
6. Remove the O-ring from the fuel injector.
7. Remove the O-ring backup from the fuel injector .

Inspection Procedure
1. Inspect the O-rings for cracks or leaks.
2. Replace worn or damaged O-rings.
3. Lubricate the new O-rings with engine oil before
installation.

Installation Procedure
1. Install the O-ring backup on the fuel injector.
2. Install the new O-ring on the fuel injector.
3. Install the fuel injector on the fuel rail.






F06RW017

4. Use new fuel injector retainer clips to retain the fuel
injector to the fuel rail.
5. Coat the end of the fuel injector with engine oil.
6. Install the fuel rail. Refer to Fuel Rail.




060RW044
7. Install the upper intake manifold. Refer to Common
Chamber in Engine Mechanical.
8. Install the engine cover.
9. Connect the negative battery cable.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-377
FUEL PRESSURE REGULATOR

Removal Procedure
CAUTION: To reduce the risk of fire and personal
injury, it is necessary to relieve the fuel system
pressure before servicing the fuel system
components.
CAUTION: After relieving the system pressure, a
small amount of fuel may be released when
servicing fuel lines or connections. Reduce the
chance of personal injury by covering the fuel line
fittings with a shop towel before disconnecting the
fittings. The towels will absorb any fuel that may
leak out. When the disconnect is completed, place
the towel in an approved container.
NOTE: Compressed air must never be used to test
or clean a fuel pressure regulator, as damage to the
fuel pressure regulator may result.
NOTE: To prevent damage to the fuel pressure
regulator, do not immerse the pressure regulator in
solvent.
1. Depressurize the fuel system. Refer to Fue
l
Pressure Relief Procedure.
2. Disconnect the negative battery cable.
3. Remove the fuel pump relay. Refer to Fuel Pump
Relay.
4. Remove the pressure regulator hose from the fuel
pressure regulator.
5. Remove the two bolts from the protector tha
t
secures the common chamber.



060RW066

6. Remove the fuel pressure regulator attaching
screw.




060RW116
7. Remove the fuel pressure regulator from the fuel
rail.

Disassembly Procedure
1. Remove the O-ring from the fuel pressure regulator.
2. Remove the fuel return line from the fuel pressure
regulator.
3. Remove the O-ring from the fuel return line.
 The O-ring may be left inside the fuel pressure
regulator instead of on the fuel return line.




060RW116

6E-378 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Assembly Procedure
1. Install a new O-ring on the fuel return line.
2. Install the fuel return line on the fuel pressure
regulator.
Do not over-tighten the swivel nut on the fuel pressure
regulator. The fuel pressure regulator can be damaged
and fuel may leak if the swivel nut is over-tightened.
3. Tighten the swivel nut.
4. Install a new O-ring on the fuel pressure regulator.

Installation Procedure
1. Install the fuel pressure regulator attaching screw.
Tighten
 Tighten the fuel pressure regulator attaching scre
w
to 3 Nm (0.3 kgm/26 lb in.).




060RW116
2. Install the fuel pressure regulator on the fuel rail.

3. Install the two bolts to the protector that secures
the common chamber.



060RW066
4. Install the pressure regulator hose to the fuel
pressure regulator.
5. Install the fuel pump relay. Refer to Fuel Pump
Relay.
6. Connect the negative battery cable.
7. Crank the engine until it starts. Cranking the engine
may take longer than usual due to trapped air in the
fuel lines.

6E-380 3.5L ENGINE DRIVEABILITY AND EMISSIONS
SPARK PLUGS

Removal Procedure
1. Remove spark plugs.

Inspection Procedure
The spark plug affects entire engine performance and
therefore its inspection is very important.
 Check electrode and insulator for presence o
f
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 (0.04 in)

1.1 mm
(0.043 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 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 o
f
standard.
Insulation resistance: 50 M
  or more




011RS010
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 cracks.
 Clean threads and metal body with a wire brush.
 File the electrode tip if electrode is extremely worn.

6E-382 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Special Tools
ILLUSTRATION PART NO.
PART NAME
ILLUSTRATION PART NO.
PART NAME
5–8840–0285–0
(J 39200)
High Impedance
Multimeter (Digital
Voltmeter – DVM) Breaker Box
(1) PCMCIA Card
(2) RS232 Loop Back
Connector
(3) SAE 16/19 Adapter
(4) DLC Cable
(5) TECH 2 5–8840–2618–0
Fuel Injector Tester
5–8840–0385–0
(J 35616-A/BT-8637)
Connector Test Adapter
Kit
5–8840–0378–0
(J 34730-E)
Port Fuel Injection
Diagnostic Kit
5–8840–2635–0
(J 39021-90)
Injector Switch Box
5–8840–0383–0
(J 26792/BT-7220-1)
Spark Tester