ISUZU TF SERIES 2004 Workshop Manual

ENGINE MECHANICAL (6VE1 3.5L) 6A-17
Engine Oil Consumption Excessive
Symptom Possible Cause Action
Oil leaking Oil pan drain plug loose Retighten or replace gasket
Crankcase fixing bolts loosened Retighten
Oil pan setting bolts loosened Retighten
Oil pan gasket broken Replace gasket
Front cover retaining bolts loose or
gasket broken Retighten or replace gasket
Head cover fixing bolts loose or
gasket broken Retighten or replace gasket
Oil filter adapter cracked Replace
Oil filter attachings bolt loose or
rubber gasket broken Retighten or replace oil filter
Oil cooler broken Replace
Crankshaft front or rear oil seal
defective Replace oil seal
Oil pressure unit loose or broken Retighten or replace
Blow–by gas hose broken Replace hose
Positive Crankcase Ventilation Valve
clogged Clean
Engine/Transmission coupling failed Replace oil seal
Oil leaking into combustion chambers
due to poor seal in valve system Valve stem oil seal defective Replace
Valve stem or valve guide worn Replace valve and valve guide
Oil leaking into combustion chambers
due to poor seal in cylinder parts Cylinders and pistons worn
excessively Replace cylinder body assembly and
pistons
Piston ring gaps incorrectly
positioned Correct
Piston rings set with wrong side up Correct
Piston ring sticking Replace cylinder body assembly and
pistons
Piston ring and ring groove worn Replace pistons and others
Return ports in oil rings clogged Clean piston and replace rings
Positive Crankcase Ventilation
System malfunctioning Positive Crankcase Ventilation Valve
clogged Clean
Others Improper oil viscosity Use oil of recommended S.A.E.
viscosity
Continuous high speed driving and/or
severe usage such as trailer towing Continuous high speed operation
and/or severe usage will normally
cause increased oil consumption

6A-18 ENGINE MECHANICAL (6VE1 3.5L)
Fuel Consumption Excessive
Symptom Possible Cause Action
Trouble in fuel system Mixture too rich or too lean due to
trouble in fuel injection system Refer to “Abnormal Combustion"
Fuel cut function does not work Refer to “Abnormal Combustion"
Trouble in ignition system Misfiring or abnormal combustion due
to trouble in ignition system Refer to “Hard Start" or “Abnormal
Combustion"
Others Engine idle speed too high Reset to Section 6E
Returning of accelerator control
sluggish Correct
Fuel system leakage Correct or replace
Clutch slipping Correct
Brake drag Correct
Selection of transmission gear
incorrect Caution operator of incorrect gear
selection
Lubrication Problems
Symptom Possible Cause Action
Oil pressure too low Wrong oil in use Replace with correct engine oil
Relief valve sticking Replace
Oil pump not operating properly Correct or replace
Oil pump strainer clogged Clean or replace strainer
Oil pump worn Replace
Oil pressure gauge defective Correct or replace
Crankshaft bearing or connecting rod
bearing worn Replace
Oil contamination Wrong oil in use Replace with correct engine oil
Oil filter clogged Replace oil filter
Cylinder head gasket damage Replace gasket
Burned gases leaking Replace piston and piston rings or
cylinder body assembly
Oil not reaching valve system Oil passage in cylinder head or
cylinder body clogged Clean or correct

ENGINE MECHANICAL (6VE1 3.5L) 6A-19
Engine Oil Pressure Check
1. Check for dirt, Fuel or water in the engine oil.
a. Check the viscosity of the oil.
b. Check the viscosity of the oil.
c. Change the oil if the viscosity is outside the
specified standard.
d. Refer to the “Maintenance and Lubrication"
section of this manual.
2. Check the engine oil level.
The level should fall somewhere between the
“ADD" and the “FULL" marks on the oil level
dipstick.
If the oil level does not reach the “ADD" mark on
the oil level dipstick, engine oil must be added.
3. Remove the oil pressure unit.
4. Install an oil pressure gauge.
5. Start the engine and allow the engine to reach
normal operating temperature (About 80C).
6. Measure the oil pressure.
Oil pressure should be:
392




550 kPa (56.9




80.4 psi) at 3000 rpm.
7. Stop the engine.
8. Remove the oil pressure gauge.
9. Install the oil pressure unit.
10. Start the engine and check for leaks.

6A-20 ENGINE MECHANICAL (6VE1 3.5L)
Malfunction Indicator Lamp
The instrument panel “CHECK ENGINE" Malfunction
Indicator Lamp (MIL) illuminates by self diagnostic
system when the system checks the starting of engine,
or senses malfunctions. ”CHECK ENGINE" MIL does
not illuminate at the starting of engine

Symptom Possible Cause Action
“CHECK ENGINE" MIL does not
illuminate at the starting of engine Bulb defective Replace
MIL circuit open Correct or replace
Command signal circuit to operate
self diagnostic system shorted Correct or replace
Engine Control Module (ECM) cable
loosely connected, disconnected or
defective Correct or replace
ECM defective Replace
“CHECK ENGINE" MIL illuminates,
and stays on Deterioration of heated oxygen
sensor internal element Replace
Heated oxygen sensor connector
terminal improper contact Reconnect properly
Heated oxygen sensor lead wire
shorted Correct
Heated oxygen sensor circuit open Correct or replace
Deterioration of engine coolant
temperature sensor internal element Replace
Engine coolant temperature sensor
connector terminal improper contact Reconnect properly
Engine coolant temperature sensor
lead wire shorted Correct
Engine coolant temperature sensor
circuit open Correct or replace
Throttle position sensor open or
shorted circuits Correct or replace
Deterioration of crankshaft position
sensor Replace
Crankshaft position sensor circuit
open or shorted Correct or replace
Vehicle speed sensor circuit open Correct or replace
Intake air temperature sensor circuit
open or shorted Correct or replace
Fuel injector circuit open or shorted Correct or replace
ECM driver transistor defective Replace ECM
Malfunctioning of ECM RAM
(Random Access Memory) or ROM
(Read Only Memory) Replace ECM

ENGINE MECHANICAL (6VE1 3.5L) 6A-21
Cylinder Head Cover LH
Removal
1. Disconnect battery ground cable.
2. Disconnect positive crankcase ventilation hose.
3. Remove camshaft angle sensor connector.
4. Remove ground cable fixing bolt on cylinder head
cover.
5. Ignition coil connector and ignition coil.

Disconnect the three connectors from the
ignition coils.

Remove harness bracket bolt on cylinder head
cover.

Remove fixing bolts on ignition coils.









060RW078
Legend
(1) Ignition Coil Connector
(2) Bolt
(3) Ignition Coil Assemblies

6. Remove fixing bolt for fuel injector harness
bracket.

7. Remove eight fixing bolts, then the cylinder head
cover.






010RW001
Installation
1. Install cylinder head cover.

Clean the sealing surface of cylinder head and
cylinder head cover to remove oil and sealing
materials completely.

Apply sealant (TB-1207B or equivalent) of bead
diameter 2-3 mm at eight place of arched area
of camshaft bracket on front and rear sides.

The cylinder head cover must be installed with
in 5 minutes after sealant application to preven
t
hardening of sealant.

Tighten bolts to the specified torque.
Torque : 9 N




m (0.9 kg




m/7 lb ft)




010RW006

6A-22 ENGINE MECHANICAL (6VE1 3.5L)
2. Install fuel injection harness bracket and tighten
bolt to the specified torque.
Torque : 8 N




m (0.8 kg




m/8 lb ft)
3. Connect ignition coil connector and ignition coil,
then tighten bolt to the specified torque.
Torque : 4 N




m (0.4 kg




m/3 lb ft)


060RW078
Legend
(1) Ignition Coil Connector
(2) Bolt
(3) Ignition Coil Assembly

4. Connect ground cable and tighten bolts to the
specified torque.
Torque : 8 N




m (0.8 kg




m/6 lb ft)
5. Connect camshaft angle sensor connector.
6. Install positive crankcase ventilation hose.

ENGINE MECHANICAL (6VE1 3.5L) 6A-23
Cylinder Head Cover RH
Removal
1. Disconnect battery ground cable.
2. Remove air cleaner duct assembly.
3. Disconnect ventilation hose from cylinder head
cover.
4. Disconnect three ignition coil connectors from
ignition coils and remove harness bracket bolts on
cylinder head cover then remove ignition coil fixing
bolts on ignition coils and remove ignition coils.
5. Remove heater pipe fixing bolts from the bracket.
6. Disconnect fuel injector harness connector then
remove fuel injector harness bracket bolt.
7. Remove eight fixing bolts then the cylinder head
cover.





010RW002
Installation
1. Install cylinder head cover.

Clean the sealing surface of cylinder head and
cylinder head cover to remove oil and sealing
materials completely.

Apply sealant (TB-1207B or equivalent) of bead
diameter 2‐3 mm at eight place of arched
area of camshaft bracket on front and rea
r
sides.

The cylinder head cover must be installed
within 5 minutes after sealant application to
prevent premature hardening of sealant.

Tighten bolts to the specified torque.
Torque : 9 N




m (0.9 kg




m/7 lb ft)





014RW019
2. Install exhaust gas recirculation pipe and tighten to
specified torque.
Torque :
Exhaust manifold side: 29 N




m (3.0 kg




m/21 lb ft)
Flare nut: 44 N




m (4.5 kg




m/33 lb ft)
Cylinder head side: 20 N




m (2.0 kg




m/14 lb ft)
3. Tighten fuel injector harness bracket bolts to
specified torque then reconnect fuel injecto
r
harness connector.
Torque : 8 N




m (0.8 kg




m/5.7 lb ft)
4. Install heater pipe bolt to the specified torque.
Torque : 20 N




m (2.0 kg




m/14 lb ft)
5. Connect ignition coil connector and tighten ignition
coil fixing bolts to specified torque.
Torque : 4 N




m (0.4 kg




m/3 lb ft)
6. Connect ventilation hose to cylinder head.
7. Install air cleaner duct assembly.

6A-24 ENGINE MECHANICAL (6VE1 3.5L)
Common Chamber
Removal
1. Disconnect battery ground cable.
2. Remove air cleaner duct assembly.
3. Remove the ECM.

Disconnect the two connectors from the ECM.

Remove fixing bolts on the common chamber.

Remove fixing bolts for ground cable.




060RW025
4. Remove the accelerator control cable from
accelerator control cable bracket.

Slide the lock in direction A

Rotate the ratchet ring in indirection an arro
w
90




RTW46ASH000201
Legend
(1) Cable Bracket
(2) Ratchet ring
(3) Outer Cap
(4) Lock
(5) Paint Mark
(6) Arrow Mark

5. Remove the accelerator control cable from the
throttle.
6. Disconnect vacuum booster hose from common
chamber.
7. Disconnect connector from manifold absolute
pressure sensor, idle air control valve, throttle
position sensor, solenoid valve, electric vacuum
sensing valve.
8. Disconnect vacuum hose on canister VSV and
positive crankcase ventilation hose, fuel rail
assembly with pressure control valve bracket.
9. Remove ventilation hose from throttle valve and
intake duct and remove water hose.
10. Remove exhaust gas recirculation valve assembly
fixing bolt and nut on common chamber.
11. Remove two bolts from common chamber rea
r
side for remove fuel hose bracket.
12. Remove common chamber four bolts and fou
r
nuts then remove the common chamber.



025RW001
Legend
(1) Common Chamber
(2) Throttle Valve Assembly
(3) Bolt

13. Remove the four throttle body fixing bolts.

ENGINE MECHANICAL (6VE1 3.5L) 6A-25
Installation
1. Install throttle body and tighten bolts to the
specified torque.
Torque : 25 N




m (2.5 kg




m/18 lb ft)
2. Install common chamber and tighten bolts and
nuts to the specified torque.
Torque :
Bolt : 18 N




m (1.8 kg




m/13 lb ft)
Nut : 18 N




m (1.8 kg




m/13 lb ft)
3. Install fuel hose bracket and tighten bolts to
specified torque.
Torque : 10 N




m (1.0 kg




m/89 lb in)
4. Install ventilating hose to throttle valve and intake
duct.
5. Connect vacuum hoses on canister VSV and
positive crankcase ventilation hose. Tighten bolts
for fuel rail assembly with pressure control valve
bracket.
Torque : 25 N




m (2.5 kg




m/18 lb ft)
6. Connect each connector without fail.
7. Connect vacuum booster hose.
8. Install the ECM.

Tighten the four bolts.
Torque : 10 N




m (1.0 kg




m/7 lb ft)

Connect the two connectors.

Tighten the two ground cable bolts.
9. Install accelerator control cable to accelerato
r
cable bracket.

Rotate the ratchet ring in direction an arrow 90

Confirm marking of outer cap must be uppe
r
side.

Slider the lock of outer cap must be upper side.

Confirm ratchet ring is locked.



060RW093
Legend
(1) Cable Bracket
(2) Ratchet ring
(3) Outer Cap
(4) Lock
(5) Paint Mark
(6) Arrow Mark

10. Install the cable clips to accelerator control cable.
11. Install air cleaner duct assembly.

6A-26 ENGINE MECHANICAL (6VE1 3.5L)
Exhaust Manifold LH
Removal
1. Disconnect battery ground cable.
2. Disconnect O
2 sensor connector.
3. Remove torsion bar. Refer to removal procedure in
Front Suspension section.
4. Remove exhaust front pipe three stud nuts from
exhaust side and two nuts from rear end o
f
exhaust front pipe.




RTW36FSH000201
5. Remove heat protector two fixing bolts then the
heat protector.
6. Remove a bolt on engine LH side for ai
r
conditioner (A/C) compressor bracket and loosen
two bolts for A/C compressor then move A/C
compressor to front side.
7. Remove exhaust manifold eight fixing nuts and
remove exhaust manifold from the engine.
Installation
1. Install exhaust manifold and tighten exhaust
manifold fixing nuts to the specified torque with
new nuts.
Torque: 52 N




m (5.3 kg




m/38 lb ft)
2. Install heat protector.
3. Install exhaust front pipe and tighten three stud
nuts and two nuts to the specified torque.
Torque:
Stud nuts: 67 N




m (6.8 kg




m/49 lb ft)
Nuts: 43 N




m (4.4 kg




m/32 lb ft)




RTW36FSH000201
4. Install the torsion bar and readjust the vehicle
height. Refer to installation and vehicle heigh
t
adjustment procedure for front suspension.
5. Set A/C compressor to normal position and tighten
two bolts and a bolt to the specified torque.
Torque : 40 N




m (4.1 kg




m/30 lb ft)
6. Reconnect O
2 sensor connector.
7. Install air cleaner duct assembly.