fuel pressure ISUZU TF SERIES 2004 Workshop Manual

ENGINE DIAGNOSIS (C24SE) 6-11
Abnormal Combustion
Condition Possible cause Correction
Trouble in fuel injection system Fuel pressure control valve
defective Replace
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
loosely connected or defective Reconnect, correct or replace
Manifold Absolute Pressure
Sensor circuit open or shorted Correct or replace
Manifold Absolute Pressure
Sensor defective Replace
Engine Coolant Temperature
(ECT) Sensor circuit open or
shorted Correct or replace
ECT Sensor defective Replace
Throttle Position Sensor
adjustment incorrect Reconnect
Throttle Position Sensor defective Replace
Throttle Position Sensor
connector loosely connected Reconnect
Vehicle Speed Sensor cable
loosely connected 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
loosely connected or defective Correct or replace
Trouble in emission control
system Heated Oxygen Sensor circuit
open (If applicable) Correct or replace
Heated Oxygen Sensor defective
(If applicable) Replace
Signal vacuum hose loosely fitted
or defective Correct or replace
ECT Sensor circuit open or
shorted Correct or replace
ECT Sensor defective Replace
Evaporative Emission Control
system (If applicable) Refer to Section 6E
Trouble in ignition system - Refer to "Engine Lacks Power"
Trouble in cylinder head parts Carbon deposits in combustion
chamber Remove carbon
Carbon deposit on valve, valve
seat and valve guide Remove carbon

ENGINE DIAGNOSIS (C24SE) 6-13
Fuel Consumption Excessive
Condition Possible cause Correction
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 act 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 Troubleshooting
Guide
Others Engine idle speed too high Reset Idle Air Control Valve
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
Oil Problems
Condition Possible cause Correction
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 new engine oil
Oil filter clogged Replace oil filter
Cylinder head gasket damage Replace gasket
Burned gases leaking Replace piston and piston rings or
rebore cylinders
Oil not reaching valve system Oil passage in cylinder head or
cylinder body clogged Clean or correct

Engine Oil Pressure Check
1. Check for dirt, gasoline or water in the engine
oil.
a. Check the viscosity of the oil.
b. Change the oil if the viscosity is outside the
specified standard.
c. 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 80
C).
6. Measure the oil pressure.
Oil pressure should be:
150 kPa(21.8 psi) at idle speed.
7. Stop the engine.
8. Remove the oil pressure gauge
9. Install the oil pressure unit.
10. Start the engine and check for leaks.

6-14 ENGINE DIAGNOSIS (C24SE)
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.

Condition Possible cause Correction
"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 heated oxygen
sensor of internal element Replace
Heated oxygen sensor connector
terminal improper contact
(If applicable) Reconnect properly
Heated oxygen sensor lead wire
shorted (If applicable) Correct
Heated oxygen sensor circuit
open (If applicable) Correct or replace
Deterioration engine coolant
temperature sensor of 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
Manifold absolute pressure sensor
circuit open or shorted 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 EPROM or ECM
Malfunctioning of ECM RAM
(Random Access Memory) or
Malfunctioning of ECM PROM
(Programmed Read Only Memory)Replace EPROM or ECM

ENGINE MECHANICAL (C24SE) 6A-3
PAGE
ENGINE EXTERNAL PARTS ............................................................................................ 6A-65
Radiator ....................................................................................................................... 6A-65
Thermostat................................................................................................................... 6A-66
Water Pump ................................................................................................................. 6A-66
Coating sealing surfaces with Silicone Grease ....................................................... 6A-67
Alternator ..................................................................................................................... 6A-67
Starter .......................................................................................................................... 6A-67
V-belt Tension of Alternator ....................................................................................... 6A-68
FUEL INJECTION SYSTEM.............................................................................................. 6A-69
Map Sensor.................................................................................................................. 6A-69
Pressure Regulator ..................................................................................................... 6A-69
ECM (Engine Control Module).................................................................................... 6A-69
ECT ............................................................................................................................... 6A-70
Idle Air Control(IAC) Valve.......................................................................................... 6A-70
Ignition Coil ................................................................................................................. 6A-70
Crank Position Sensor................................................................................................ 6A-71
FUEL INJECTOR .............................................................................................................. 6A-72
Knock Sensor .............................................................................................................. 6A-72
Oxygen Sensor ............................................................................................................ 6A-73
Throttle Valve Position Sensor .................................................................................. 6A-73
Acclelerator Pedal and Cable..................................................................................... 6A-73
Air Cleaner Filter ......................................................................................................... 6A-74
Spark Plug Thread ...................................................................................................... 6A-75
TECHNICAL DATA ........................................................................................................... 6A-76
Recommended Troque Values................................................................................... 6A-87
SPECIAL SERVICE TOOL................................................................................................ 6A-88

ENGINE MECHANICAL (C24SE) 6A-11
Main Data and Specifications
Engine - General C24SE
Engine type Four-cycle, water cooled cross-flow with single over head
camshaft
Micro-computer control, fuel injection
Combustion chamber type (Volume) Hemispherical (43.3cm3)
Timing train system Belt drive
No. of cylinders-bore
stroke mm (in) 4-87.5
100.0 (3.44
3.93)
Bore Spacing(C/L to C/L) 93.0 mm (3.66 in)
Firing Order 1-3-4-2
Bore
Stroke mm (in) 87.5
100.0 (3.44
3.93)
Total piston displacement cm3 (in3) 2,405(146.80)
Combustion Chamber Volume 43.3cm3
No. of piston ring Compression ring: 2, Oil ring: 1
Compression pressure kg/cm2 (psi/pa) 12.2-16.3 (174-232/1200-1600)
Ignition timing (BTDC) No adjustment
Idling speed: rpm(WO/AC,W/AC) A/C off 825
Valve clearances (At cold)
Intake mm (in) 0 (0) (Hydraulic valve lash adjustment)
Exhaust mm (in) 0 (0) ( " )
Open at (BTDC) deg 1730’
Close at (ABDC) deg 7630’
Exhaust valves
Open at (BBDC) deg 5830’
Close at (ATDC) deg 3530’
Ignition system Fully transistorized battery ignition
Distributor type Not applicable, Electronic Spark Timing control
Distributor advance type Not applicable, Electronic Spark Timing control
Spark plug type RN9YC4
Spark plug gap mm (in) 1.0--1.1 (0.039--0.043)
Lubrication system
Lubricating method Fully flow pressure circulation
Special engine oil (API grade) SE, SF, SG or SH grade
Oil pressure kg/cm2 (psi/Pa) rpm 4-4.6 (56.9-65.4/400-450)
Oil pump type Gear
Oil filter type Cartridge full flow
Oil capacity lit. (US/UK gal.) 4.25
Cooling system
Radiator type Corrugated fin with reserve tank
Coolant capacity lit.
(US/UK gal.) 2.3 (0.66/0.55)
Water pump type Centrifugal
Thermostat Wax pellet with jiggle hole

6A-12 ENGINE MECHANICAL (C24SE)
Engine - General C24SE
Fuel system Electronically controlled Multi Port Fuel Injection System
Fuel pump type Electric
Fuel pressure kg/cm2 (psi/Pa) 3.4 (48.4/334)
Fuel filter type Cartridge paper element
Air cleaner type Dry paper element
Battery Type/V-Ax No. of units 34B19L/50D20L
Alternator
Capacity V-A(W) 12-90 (1080), 12-100 (1200)
Starter
Output V-kW 1.4
Exhaust system CO Adjustment (1) Applicable to Open Loop System (Not equipped H2OS)
(2) Not applicable to Closed Loop System (Equipped H2OS)
Compression Ratio (with Tolerance) 9.6:10.25
Cylinder Head Material Aluminum Alloy (gravity cast)
Cylinder Block Material Cast Iron
No. of Mounting Points (including trans.) 3
Engine Installation Angles
-Longitudinal4 60'
-Lateral 7 50' (towards exhaust side)
Overall Dimensions (L




W




H):
- TF (2.4Litre/2WD) 610
564
708mm
- TF (2.4Litre/4WD) 610
564
746mm
Engine Weight
Engine Weight
- TF (2.4Liter/Man)140kg
Camshaft Type SOHC
No. of Valves per Cylinder
- Inlet1
- Exhaust 1
Spark Plug Location Side
Port Arrangement Cross Flow
Working Principle Spark Ignition 4-stroke

ENGINE MECHANICAL (C24SE) 6A-69
FUEL INJECTION SYSTEM
MAP SENSOR


Removal
1. Disconnect the battery cable.
2. Disconnect the electrical connector from the sensor.
3. Remove the mounting bolts securing the sensor to the manifold.
4. Remove the sensor from the intake manifold.


Installation
1. Push MAP sensor into the manifold.
2. Install the mounting bolts and tighten them.
3. Connect electrical connector.
4. Connect the battery cable.









Pressure Regulator
Removal
1. Remove vacuum hose.
2. Remove fuel hoses.
3. Remove pressure regulator.

Installation
1. Install pressure regulator.
2. Install fuel hoses.
3. Install vacuum hoses.


ECM (Engine Control Module)
Removal

(2.4L)
1. Disconnect the ECM connector.
2. Remove the four hex bolts and nuts.
3. Remove the ECM from the ECM bracket on engine.

6A-72 ENGINE MECHANICAL (C24SE)
FUEL INJECTOR



Removal
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 fuel 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 fitting with a shop 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. Depressurize the fuel system.
2. Disconnect the fuel inlet.
3. Disconnect the fuel return line.
4. Remove the fuel rail from the intake manifold.
5. Remove the fuel injector from the fuel rail by disengaging
claws.

Installation
1. Install the fuel injector to the fuel rail by engaging claws.
2. Install the fuel rail to the intake manifold.
3. Connect the fuel return line firmly.
4. Connect the fuel supply line firmly.





Knock sensor
Removal
1. Remove fixing bolts.
2. Disconnect the connector at the other side.


Tighten (Torque)
Oxygen sensor in exhaust pipe - 30N

m (3.2 kgf

m)
When re-using, insert oxygen sensor.

ENGINE FUEL (C24SE) 6C-3


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 if 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.



Service Precaution
CAUTION:
Always use the correct fastener in the proper location.
When you replace a fastener, use ONLY the exact part
number for that application. ISUZU will call out those
fasteners that require a replacement after removal. ISUZU
will also call out the fasteners that require thread lockers
or thread sealant. UNLESS OTHERWISE SPECIFIED, do
not use supplemental coatings (Paints, greases, or othe
r
corrosion inhibitors) on threaded fasteners or fastene
r
joint interfaces. Generally, such coatings adversely affect
the fastener torque and the joint clamping force, and may
damage the fastener. When you install fasteners, use the
correct tightening sequence and specifications. Following
these instructions can help you avoid damage to parts
and systems.

6C-4 ENGINE FUEL (C24SE)

Fuel Metering
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 Manifold Absolute Pressure (MAP) sensor measures the
changes in the intake manifold pressure which result from
engine load and speed changes, which the MAP senso
r
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 MAP 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 crankshaft revolution. The
ECM controls the injector on time so that the correct amount o
f
fuel is metered depending on driving conditions.
Two interchangeable "O" rings are used on the injector tha
t
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 weather 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.