2004 ISUZU TF SERIES fuel pressure

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.

6C-2 ENGINE FUEL (6VE1 3.5L)
General Description







RTW36CLF000301
Legend (8) Fuel Rail Left
(1) Fuel Filler Cap (9) Intake Air Port Left Bank
(2) Fuel Tank (10) Fuel Pressure Control Valve
(3) Rollover Valve (11) Common Chamber
(4) Fuel Pump and Sender Assembly (12) Duty Solenoid Valve
(5) Fuel Filter (13) Throttle Valve
(6) Fuel Rail Right (14) Canister
(7) Intake Air Port Right Bank (15) Evapo Control Valve

ENGINE FUEL (6VE1 3.5L) 6C-3
Fuel Metering
The Engine Control Module (ECM) is in complete
control of this fuel delivery system during normal driving
conditions.
The intake manifold function, like that of a diesel, is
used only to let air into the engine. The fuel is injected
by separate injectors that are mounted over the intake
manifold.
The Barometric Pressure (BARO) sensor measures the
changes in the barometric pressure which result from
engine load and speed changes, which the BARO
sensor converts to a voltage output.
This sensor generates the voltage to change
corresponding to the flow of the air drawn into the
engine.
The changing voltage is transformed into an electric
signal and provided to the ECM.
With receipt of the signals sent from the BARO sensor,
Intake Air Temperature sensor and others, the ECM
determines an appropriate fuel injection pulse width
feeding such information to the fuel injector valves to
effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection
system where the injectors turn on at every crankshaf
t
revolution. The ECM controls the injector on time so
that the correct amount of fuel is metered depending on
driving conditions.
Two interchangeable “O" rings are used on the injecto
r
that must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold
and supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the
engine is running. This removes air and vapors from the
fuel as well as keeping the fuel cool during hot weathe
r
operation.
The fuel pressure control valve that is mounted on the
fuel rail maintains a pressure differential across the
injectors under all operating conditions. It is
accomplished by controlling the amount of fuel that is
recirculated back to the fuel tank based on engine
demand.
See Section “Driveability and Emission" for more
information and diagnosis.