fuel pressure ISUZU TF SERIES 2004 Repair Manual

ENGINE MECHANICAL (6VE1 3.5L) 6A-3
General Description
Engine Cleanliness And Care
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the thousandths of a
millimeter (ten thousandths of an inch). Accordingly,
when any internal engine parts are serviced, care and
cleanliness are important. Throughout this section, i
t
should be understood that proper cleaning and
protection of machined surfaces and friction areas is
part of the repair procedure. This is considered
standard shop practice even if not specifically stated.


A liberal coating of engine oil should be applied to
all friction areas during assembly to protect and
lubricate the surfaces on initial operation.

Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and
crankshaft journal bearings are removed fo
r
service, they should be retained in order.


At the time of installation, they should be installed
in the same locations and with the same mating
surfaces as when removed.

Battery cables should be disconnected before any
major work is performed on the engine. Failure to
disconnect cables may result in damage to wire
harness or other electrical parts.

The six cylinders of this engine are identified by
numbers; Right side cylinders 1, 3 and 5, Left side
cylinders 2, 4 and 6, as counted from crankshaf
t
pulley side to flywheel side.
General Information on Engine Service
The following information on engine service should be
noted carefully, as it is important in preventing damage
and contributing to reliable engine performance.

When raising or supporting the engine for any
reason, do not use a jack under the oil pan. Due to
the small clearance between the oil pan and the oil
pump strainer, jacking against the oil pan may
cause damage to the oil pick-up unit.

The 12-volt electrical system is capable o
f
damaging circuits. When performing any work
where electrical terminals could possibly be
grounded, the ground cable of the battery should
be disconnected at the battery.


Any time the intake air duct or air cleaner is
removed, the intake opening should be covered.
This will protect against accidental entrance o
f
foreign material into the cylinder which could
cause extensive damage when the engine is
started.
Cylinder Block
The cylinder block is made of aluminum die-cast casting
for 75Vtype six cylinders. It has a rear plate integrated
structure and employs a deep skirt. The cylinder liner is
cast and the liner inner diameter and crankshaft journal
diameter are classified into grades. The crankshaft is
supported by four bearings of which width is differen
t
between No.2, No.3 and No.1, No.4; the width of No.3
bearing on the body side is different in order to suppor
t
the thrust bearing. The bearing cap is made of nodular
cast iron and each bearing cap uses four bolts and two
side bolts.
Cylinder Head
The cylinder head, made of aluminum alloy casting
employs a pent-roof type combustion chamber with a
spark plug in the center. The intake and exhaust valves
are placed in V-type design. The ports are cross-flo
w
type.
Valve Train
Intake and exhaust camshaft on the both side of banks
are driven through an camshaft drive gear by timing
belt. The valves are operated by the camshaft and the
valve clearance is adjusted to select suitable thickness
shim.
Intake Manifold
The intake manifold system is composed of the
aluminum cast common chamber and intake manifold
attached with six fuel injectors.
Exhaust Manifold
The exhaust manifold is made of nodular cast iron.
Pistons and Connecting Rods
Aluminum pistons are used after selecting the grade
that meets the cylinder bore diameter. Each piston has
two compression rings and one oil ring. The piston pin
made of chromium steel is offset 1mm toward the thrus
t
side, and the thrust pressure of piston to the cylinder
wall varies gradually as the piston travels. The
connecting rods are made of forged steel. The
connecting rod bearings are graded for correct size
selection.
Crankshaft and Bearings
The crankshaft is made of Ductile cast-iron. Pins and
journals are graded for correct size selection for thei
r
bearing.
Engine Control Module (ECM)
The ECM location is on the common charmber.

ENGINE MECHANICAL (6VE1 3.5L) 6A-5
3. Trouble In Fuel System
Symptom Possible Cause Action
Starting motor turns over and spark
occurs but engine does not start. Fuel tank empty Fill
Water in fuel system Clean
Fuel filter clogged Replace filter
Fuel pipe clogged Clean or replace
Fuel pump defective Replace
Fuel pump circuit open Correct or replace
Evaporative Emission Control System
circuit clogged Correct or replace
Multiport Fuel Injection System faultyRefer to “Electronic Fuel Injection"
section

4. Engine Lacks Compression
Symptom Possible Cause Action
Engine lacks compression Spark plug loosely fitted Tighten to specified torque
Valve timing incorrect Adjust
Cylinder head gasket defective Replace gasket
Valve incorrectly seated Lap valve
Valve stem seized Replace valve and valve guide
Valve spring weakened or broken Replace
Cylinder or piston rings worn Overhaul engine
Piston ring seized Overhaul engine.

Engine Compression Test Procedure
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and
fuse box.
6. Engage the starter and check that the cranking
speed is approximately 300 rpm.
7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the
starter engaged until the compression gage needle
reaches the maximum level. Note the reading.
9. Repeat the test with each cylinder.
If the compression pressure obtained falls belo
w
the limit, engine overhaul is necessary.
Limit; 1000 kPa (145 psi)

6A-8 ENGINE MECHANICAL (6VE1 3.5L)
Hesitation
Symptom Possible Cause Action
Hesitation on acceleration Throttle Position Sensor adjustment
incorrect Replace throttle valve assembly
Throttle Position Sensor circuit open
or shorted Correct or replace
Excessive play in accelerator linkageAdjust or replace
Mass Airflow Sensor circuit open or
poor connections Correct or replace
Mass Airflow Sensor defective Replace
Intake Air Temperature (IAT) Sensor
circuit open or poor connections Correct or replace
IAT Sensor defective Replace
Hesitation at high speeds
(Fuel pressure too low) Fuel tank strainer clogged Clean or replace
Fuel pipe clogged Clean or replace
Fuel filter clogged Replace
Defective fuel pump system Check and replace
Fuel Pressure Control Valve leaking Replace
Hesitation at high speeds
(Fuel injector not working normally) Power supply or ground circuit for
Multiport Fuel Injection System
shorted or open Check and correct or replace
Fuel Injector defective Replace
Cable of Multiport Fuel Injection
System circuit open or poor
connections Correct or replace

6A-10 ENGINE MECHANICAL (6VE1 3.5L)
Engine Lacks Power
Symptom Possible Cause Action
Trouble in fuel system Fuel Pressure Control Valve not
working normally Replace
Fuel injector clogged Clean or replace
Fuel pipe clogged Clean
Fuel filter clogged or fouled Replace
Fuel pump drive circuit not working
normally Correct or replace
Fuel tank not sufficiently breathing
due to clogged Evaporative Emission
Control System circuit Clean or replace
Water in fuel system Clean
Inferior quality fuel in fuel system Use fuel of specified octane rating
Engine Control Module supplied poor
voltage Correct circuit
Throttle Position Sensor cable broken
or poor connections Correct or replace
Throttle Position Sensor defective Replace
Mass Airflow Sensor not working
normally Replace
Manifold Absolute Pressure Sensor
not working normally Replace
Intake Air Temperature Sensor not
working normally Replace
Engine Coolant Temperature Sensor
circuit open or shorted Correct or replace
Engine Coolant Temperature Sensor
defective Replace
Engine Control Module defective Replace
Trouble in intake or exhaust system Air Cleaner Filter clogged Replace filter element
Air duct kinked or flattened Correct or replace
Exhaust system clogged Correct or replace
Ignition failure ———— Refer to Hard Start Troubleshooting
Guide
Heat range of spark plug inadequateInstall spark plugs of adequate heat
range
Ignition coil defective Replace

ENGINE MECHANICAL (6VE1 3.5L) 6A-15
Abnormal Combustion
Symptom Possible Cause Action
Trouble in fuel system Fuel pressure control valve defectiveReplace
Fuel filter clogged Replace
Fuel pump clogged Clean or replace
Fuel tank or fuel pipe clogged Clean or replace
Fuel injector clogged Clean or replace
Fuel pump relay defective Replace
Power supply cable for fuel pump
broken or poor connections Reconnect, correct or replace
Mass Airflow (MAF) Sensor circuit
open or defective Correct or replace
MAF Sensor defective Replace
Engine Coolant Temperature (ECT)
Sensor circuit open or shorted Correct or replace
ECT Sensor defective Replace
Throttle Position Sensor adjustment
incorrect Readjust
Throttle Position Sensor defective Replace
Throttle Position Sensor connector
poor connections Reconnect
Vehicle Speed Sensor cable poor
connections or defective Correct or replace
Vehicle Speed Sensor loosely fixed Fix tightly
Vehicle Speed Sensor in wrong
contact or defective Replace
Engine Control Module cable poor
connections or defective Correct or replace

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-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.

ENGINE FUEL (6VE1 3.5L) 6C-1
ENGINE
ENGINE FUEL (6VE1 3.5L)
CONTENTS

Service Precaution................................................. 6C-1
General Description............................................... 6C-2
Fuel Metering.......................................................... 6C-3
Fuel Filter................................................................. 6C-4
Removal............................................................... 6C-4
Inspection............................................................. 6C-4
Installation............................................................ 6C-4
Inspection............................................................. 6C-4
In-Tank Fuel Filter............................................... 6C-4
Fuel Pump Flow Test......................................... 6C-4
Fuel Pump............................................................... 6C-6
Fuel Pump and Associated Parts..................... 6C-6
Removal............................................................... 6C-6
Installation............................................................ 6C-7
Fuel Tube / Quick - Connector Fittings............... 6C-8
Precautions.......................................................... 6C-8
Cautions During Work........................................ 6C-8

Removal................................................................ 6C-8
Reuse of Quick-Connector................................. 6C-9
Assembling Advice.............................................. 6C-9
Fuel Pump Relay..................................................... 6C-10
General Description............................................ 6C-10
Fuel Tank................................................................. 6C-11
Fuel Tank and Associated Parts....................... 6C-11
Removal................................................................ 6C-11
Installation............................................................. 6C-12
Filler Neck................................................................ 6C-13
Removal................................................................ 6C-13
Installation............................................................. 6C-13
Fuel Gauge Unit...................................................... 6C-13
Removal and Installation.................................... 6C-13
Fuel Filler Cap......................................................... 6C-14
General Description............................................ 6C-14
Inspection............................................................. 6C-14
Main Data and Specifications................................ 6C-15
Special Tool.......................................................... 6C-16


Service Precaution
When working on the fuel system, there are several
things to keep in mind:
 Any time the fuel system is being worked on,
disconnect the negative battery cable except
for those tests where battery voltage is
required.
 Always keep a dry chemical (Class B) fire
extinguisher near the work area.
 Replace all pipes with the same pipe and
fittings that were removed.
 Clean and inspect “O" rings. Replace i
f
required.
 Always relieve the line pressure before
servicing any fuel system components.
 Do not attempt repairs on the fuel system until
you have read the instructions and checked
the pictures relating to that repair.
 Adhere to all Notices and Cautions.


All gasoline engines are designed to use only
unleaded gasoline. Unleaded gasoline must be
used for proper emission control system operation.
Its use will also minimize spark plug fouling and
extend engine oil life. Using leaded gasoline can
damage the emission control system and could
result in loss of emission warranty coverage.
All cars are equipped with an Evaporative Emission
Control System. The purpose of the system is to
minimize the escape of fuel vapors to the
atmosphere.