stop start ISUZU TF SERIES 2004 Owner's Guide
[x] Cancel search | Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 2106 of 4264

6E-110 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value(s) YES NO
9
1. Connect the 5–8840–2618–0 Fuel Injector Tester
and 5–8840–2635–0 Injector Switch Box the fuel
injector harness connector.
2. Set the amperage supply selector switch on the
fuel injector tester to the “Balance Test" 0.5-2.5
amp position.
3. Using the Tech 2 turn the fuel pump “ON" then
“OFF" in order to pressurize the fuel system.
4. Record the fuel pressure indicated by the fuel
pressure gauge after the fuel pressure stabilizes.
This is the first pressure reading.
5. Energize the fuel injector by depressing the “Push
to Start Test" button on the fuel injector tester.
6. Record the fuel pressure indicated by the fuel
pressure gauge after the fuel pressure gauge
needle has stopped moving. This is the second
pressure reading.
7. Repeat steps 1 through 6 for each fuel injector.
8. Subtract the second pressure reading from the first
pressure reading for one fuel injector. The result
is the pressure drop value.
9. Obtain a pressure drop value for each fuel injector.
10. Add all of the individual pressure drop values.
This is the total pressure drop.
11. Divide the total pressure drop by the number of
fuel injectors. This is the average pressure drop.
Does any fuel injector have a pressure drop value that
is either higher than the average pressure drop or
lower than the average pressure drop by the specified
value? 10 kPa
(1.5 psi) Go to Step 10 Go to OBD
System Check
10 Re-test any fuel injector that does not meet the
specification. Refer to the procedure in step 11.
Do not repeat any portion of this test before running
the engine in order to prevent the engine from
flooding.
Does any fuel injector still have a pressure drop value
that is either higher than the average pressure drop or
lower than the average pressure drop by the specified
value? 10 kPa
(1.5 psi) Go to Step 11 Go to
Symptoms
11 Replace the faulty fuel injector(s). Refer to Fuel
Injector.
Is the action complete? — Verify repair —
Page 2113 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-117
CIRCUIT DESCRIPTION
When the ignition switch is turned “ON," the Engine
Control Module (ECM) will turn “ON" the in-tank fuel
pump. The in-tank fuel pump will remain “ON" as long
as the engine is cranking or running and the ECM is
receiving 58X crankshaft position pulses. If there are no
58X crankshaft position pulses, the ECM will turn the
in-tank fuel pump “OFF" 2 seconds after the ignition
switch is turned “ON" or 2 seconds after the engine
stops running.
The in-tank fuel pump is an electric pump within an
integral reservoir. The in-tank fuel pump supplies fuel
through an in-line fuel filter to the fuel rail assembly. The
fuel pump is designed to provide fuel at a pressure
above the pressure needed by the fuel injectors. A fuel
pressure regulator, attached to the fuel rail, keeps the
fuel available to the fuel injectors at a regulated
pressure. Unused fuel is returned to the fuel tank by a
separate fuel return line.
TEST DESCRIPTION
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Connect the fuel pressure gauge to the fuel feed line
as shown in the fuel system illustration. Wrap a shop
towel around the fuel pressure connection in order to
absorb any fuel leakage that may occur when
installing the fuel pressure gauge. With the ignition
switch “ON" and the fuel pump running, the fuel
pressure indicated by the fuel pressure gauge
should be 333-376 kPa (3.4-3.8 kg/cm
2 / 48-55 psi).
This pressure is controlled by the amount o
f
pressure the spring inside the fuel pressure regulator
can provide.
3. A fuel system that cannot maintain a constant fuel
pressure has a leak in one or more of the following
areas:
The fuel pump check valve.
The fuel pump flex line.
The valve or valve seat within the fuel pressure
regulator.
The fuel injector(s).
4. Fuel pressure that drops off during acceleration,
cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using
a Tech 1 Tech 2. If an extremely lean condition
occurs, the oxygen sensor(s) will stop toggling. The
oxygen sensor output voltage(s) will drop below 500
mV. Also, the fuel injector pulse width will increase.
Important: Make sure the fuel system is not operating
in the “Fuel Cut-Off Mode."
When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulato
r
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly
as the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine “OFF."
16.Check the spark plug associated with a particula
r
fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. I
f
checking the spark plug associated with a particular
fuel injector for fouling or saturation does no
t
determine that a particular fuel injector is leaking,
use the following procedure:
Remove the fuel rail, but leave the fuel lines and
injectors connected to the fuel rail. Refer to Fue
l
Rail Assembly in On-Vehicle Service.
Lift the fuel rail just enough to leave the fuel
injector nozzles in the fuel injector ports.
CAUTION: In order to reduce the risk of fire and
personal injury that may result from fuel spraying
on the engine, verify that the fuel rail is positioned
over the fuel injector ports and verify that the fuel
injector retaining clips are intact.
Pressurize the fuel system by connecting a 10
amp fused jumper between B+ and the fuel pump
relay connector.
Visually and physically inspect the fuel injector
nozzles for leaks.
17. A rich condition may result from the fuel pressure
being above 376 kPa (55 psi). A rich condition may
cause a DTC P0132 or a DTC P0172 to set.
Driveability conditions associated with rich conditions
can include hard starting (followed by black smoke)
and a strong sulfur smell in the exhaust.
20.This test determines if the high fuel pressure is due
to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.
21.A lean condition may result from fuel pressure belo
w
333 kPa (48 psi). A lean condition may cause a DTC
P0131 or a DTC P0171 to set. Driveability conditions
associated with lean conditions can include hard
starting (when the engine is cold ), hesitation, poo
r
driveability, lack of power, surging , and misfiring.
Page 2115 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-119
Fuel System Diagnosis
Step Action Value(s) YES NO
1
Was the “On-Board Diagnostic (OBD) System Check"
performed? — Go to Step 2 Go to OBD
System Check
2
1. Turn the ignition “OFF."
2. Turn the air conditioning system “OFF."
3. Relieve fuel system pressure and install the fuel
pressure gauge.
Refer to 6E-118 FUEL GAUGE INSTALLATION
4. Turn the ignition “ON."
NOTE: The fuel pump will run for approximately 2
seconds. Use the Tech 2 to command the fuel
pump “ON".
5. Observe the fuel pressure indicated by the fuel
pressure gauge with the fuel pump running.
Is the fuel pressure within the specified limits? 290-376 kPa
(42-55 psi) Go to Step 3 Go to Step 17
3
The fuel pressure will drop when the fuel pump stops
running, then it should stabilize and remain constant.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant? — Go to Step 4 Go to Step 12
4
1. When the vehicle is at normal operation
temperature, turn the ignition “ON" to build fuel
pressure and observe the measurement on the
gauge.
2. Start the engine and observe the fuel pressure
gauge.
Did the reading drop by the amount specified after the
engine was started? 21-105 kPa
(3-15 psi) Go to Step 5 Go to Step 9
5
Is fuel pressure dropping off during acceleration,
cruise, or hard cornering? — Go to Step 6 Check for
improper fuel
6 Visually and physically inspect the following items for
a restriction:
The in-line fuel filter.
The fuel feed line.
Was a restriction found? — Verify repair Go to Step 7
7 Remove the fuel tank and visually and physically
inspect the following items:
The fuel pump strainer for a restriction.
The fuel line for a leak.
Verify that the correct fuel pump is in the vehicle.
Was a problem found in any of these areas? — Verify repair Go to Step 8
Page 2415 of 4264

ENGINE DIAGNOSIS (C24SE) 6-9
Abnormal Noise Due to Hydraulic Lash Adjuster
Should abnormal noise due to the hydraulic lash
adjuster trouble be heard immediately after the engine
is started, inspect as follows:
Condition Possible cause Correction
Abnormal noise is heard Air contaminated Bleed
HLA is spongy Check ball valve broken Repair
Safety valve in cylinder head
broken Replace
Valve clearance is not zero HLA inside stick Replace HLA assembly
Troubleshooting Procedure
Short out each spark plug in sequence using insulated
spark plug wire removers. Locate cylinder with
defective bearing by listening for abnormal noise that
stops when spark plug is shorted out.
Condition Possible cause Correction
Noise from connecting rods or
from connecting rod bearings
(Faulty connecting rods or
connecting rod bearings usually
make an abnormal noise slightly
higher than the crank bearing
noise, which becomes more
evident when engine is
accelerated) Bearing or crankshaft pin worn Replace connecting rod bearings
and crankshaft or regrind
crankshaft and install the under
size bearing
Crankpin out of round Replace connecting rod bearings
and crankshaft or regrind
crankshaft and install the under
size bearing
Connecting rod bent Correct or replace
Connecting rod bearing seized Replace connecting rod bearings
and crankshaft or regrind
crankshaft and install the under
size bearing
Troubleshooting Procedure
Abnormal noise stops when the spark plug on the
cylinder with defective parts is shorted out.
Condition Possible cause Correction
Piston and cylinder
(Faulty piston or cylinder usually
makes a combined mechanical
thumping noise which increases
when engine is suddenly
accelerated but diminishes
gradually as the engine warms up) Piston clearance increased due to
cylinder wear Replace piston and cylinder body
Piston seized Replace piston and cylinder body
Piston ring broken Replace piston and cylinder body
Piston defective Replace pistons and others
Page 2419 of 4264

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 80C).
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.
Page 2516 of 4264

6B-6 ENGINE COOLING
Draining and Refilling Cooling
System
Before draining the cooling system, inspect the system and
perform any necessary service to ensure that it is clean, does
not leak and is in proper working order. The engine coolant
(EC) level should be between the "MIN" and "MAX" lines of
reserve tank when the engine is cold. If low, check for leakage
and add EC up to the "MAX" line. There should not be any
excessive deposit of rust or scales around the radiator cap or
radiator filler hole, and the EC should also be free from oil.
Replace the EC if excessively dirty.
1. Completely drain the cooling system by opening the drain
plug at the bottom of the radiator.
2. Remove the radiator cap.
WARNING: TO AVOID THE DANGER OF BEING BURNED,
DO NOT REMOVE THE CAP WHILE THE ENGINE AND
RADIATOR ARE STILL HOT. SCALDING FLUID AND
STEAM CAN BE BLOWN OUT UNDER PRESSURE.
3. Disconnect all hoses from the EC reserve tank.
Scrub and clean the inside of the reserve tank with soap
and water. Flush it well with clean water, then drain it. Install
the reserve tank and hoses.
4. Refill the cooling system with the EC using a solution that is
at least 50 percent antifreeze.
5. Fill the radiator to the base of the filler neck.
Fill the EC reserve tank to "MAX" line when the engine is
cold.
6. Block the drive wheels and firmly apply the parking brake.
Shift an automatic transmission to "P" (Park) or a manual
transmission to neutral.
7. Remove the radiator cap. Start the engine and warm it up a
t
2,500 - 3,000 rpm for about 30 minutes.
8. When the air comes out from the radiator filler neck and the
EC level has gone down, replenish with the EC. Repeat this
procedure until the EC level does not go down. Then stop
the engine and install the radiator cap. Let the engine cool
down.
9. After the engine has cooled, replenish with EC up to the
"MAX" line of the reserve tank.
10. Start the engine. With the engine running at 3,000 rpm,
make sure there is no running water sound from the heate
r
core (behind the center console).
11. If the running water sound is heard, repeat steps 8 to 10.
Page 2519 of 4264

ENGINE COOLING 6B-9
Thermostat
Removal
1. Disconnect battery ground cable.
2. Drain engine coolant from the radiator and engine.
3. Disconnect radiator hose from the inlet pipe.
4. Remove thermostat housing.
5. Remove thermostat from thermostat housing.
Inspection
Suspend the thermostat in a water-filled container using thin
wire. Place a thermometer next to the thermostat.
Do not directly heat the thermostat.
Gradually increase the water temperature. Stir the water so
that the entire water is same temperature.
Confirm the temperature when the valve first begins to open.
Valve opening temperature 92
C (197.6
F)
Confirm the temperature when the valve is fully opened.
Valve full open temperature 107
C(224.6
F)
Make necessary repair and parts replacement if extreme wear
or damage is found during inspection.
Installation
1. Before installing thermostat, coat sealing surface with
silicon grease.
2. Install O-ring.
3. Install thermostat housing and tighten bolts to the specified
torque.
Torque: 15 N
m (1.5 kgf
m)
4. Installation rubber hose.
5. Replenish engine coolant (EC).
6. Start engine and check for EC leakage.
Fan Clutch with Cooling Fan
Inspection and Repair
Make necessary correction or parts replacement if wear,
damage or any other abnormal condition are found through
inspection.
Visually inspect for damage, leak (silicon grease) or other
abnormal conditions.
1. Inspection (on-vehicle)
1) Turn the fan clutch by hand when in a low temperature
condition before starting the engine, and confirm that it
can be turned readily.
2) Start the engine to warm it up until the temperature at the
fan clutch portion gets to around 80C. Then stop the
engine and confirm that the fan clutch can be turned with
considerable effort (clutch torque) when turned by hand.
Page 2523 of 4264

ENGINE COOLING 6B-13
Installation
1. Install radiator assembly, taking care not to damage the
radiator core.
2. Install the radiator assembly.
3. Connect reserve tank hose.
4. Connect radiator inlet hose and outlet hose.
5. Pour engine coolant up to filler neck of radiator, and up to
MAX mark of reserve tank.
Important operation (in case of 100% engine coolan
t
change) procedure for filling with engine coolant.
Remove radiator cap.
Fill with engine coolant (EC) to the radiator filler neck.
Fill with EC to the "MAX" line on the reservoir tank.
Start the engine with the radiator cap removed and bring to
operating temperature by running engine at 2,500 - 3,000
rpm for 30 minutes.
By EC temperature gauge reading make sure that the
thermostat is open.
If air bubbles come up to the radiator filler neck, replenish
with EC. Repeat until the EC level does not drop any further.
Install the radiator cap and stop the engine.
Replenish EC to the "MAX" line on the reservoir tank and
leave as it is until the engine gets cool.
After the engine gets cool, start the engine and make sure
there is no water running noise heard from the heater core
while the engine runs at 3000 rpm.
Should water running noise be heard, repeat the same
procedure from the beginning.
Main Data and Specifications
General Specifications
Cooling system Engine Coolant forced circulation
Radiator Tube type corrugated (2 tube in row)
Heat radiation capacity 66.3 kcal/h
Heat radiation area 7.08 m2
Radiator front area 028 m2
Radiator dry (weight) 3.1 kg
Radiator cap valve opening pressure 93.3 – 122.7 kpa
Engine coolant capacity 2.0L
Engine coolant pump Centrifugal type
Thermostat Bypass type
Engine coolant total capacity 5.7lit
Page 2530 of 4264

6C-6 ENGINE FUEL (C24SE)
Fuel Filter
Inspection
1. Replace the fuel filter if the fuel leaks from fuel filter
body or if the fuel filter body itself is damaged.
2. Replace the filter if it is clogged with dirt o
r
sediment.
Installation
1. Install the filter to holder from side member side.
NOTE: Attend direction of fuel filter. (1) to engine side
(2) to fuel tank side.
NOTE: Verify to hang holder hook to fuel filter.
NOTE: Verify to hang holder hook to fuel filter.
RTW36CSH000301
2. Connect the quick connector from the fuel tube to
the fuel filter.
NOTE: Pull of the left checker into the fuel pipe.
NOTE: Refer to “Fuel Tube/Quick Connector Fittings” in
this section when performing any repairs.
3. Tighten fuel filler cap until at least one click are
heard.
4. Connect the battery ground cable.
Inspection
After installation, start engine and check for fuel
leakage.
In–Tank Fuel Filter
The filter is located on the lower end of fuel pickup tube
in the fuel tank. It prevents dirt from entering the fuel
pipe and also stops water unless the filter is completely
submerged in the water. It is a selfcleaning type, no
t
requiring scheduled maintenance. Excess water and
sediment in the tank restricts fuel supply to the engine,
resulting in engine stoppage. In such a case, the tank
must be cleaned thoroughly.
Page 2538 of 4264

6C-14 ENGINE FUEL (C24SE)
Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section “Driveability and Emission".
1. Disconnect battery ground cable.
2. Loosen slowly the fuel filler cap.
NOTE: To prevent spouting out fuel to change the
pressure in the fuel tank.
NOTE: Cover opening of the filler neck to prevent any
dust entering.
3. Jack up the vehicle.
4. Support underneath of the fuel tank with a lifter.
5. Remove the inner liner of the wheel house on rea
r
left side.
6. Remove fasten bolt to the filler neck from the
body.
7. Disconnect the quick connector (8) into the fuel
tube from the fuel pipe and the evapo tube from
evapo joint connector.
NOTE: Cover the quick connector to prevent any dus
t
entering and fuel leaking.
NOTE: Refer to “Fuel Tube/Quick Connector Fittings” in
this section when performing any repairs.
8. Remove fasten bolt (1) to the tank band and the
tank band (2).
9. Disconnect the pump and sender connector on the
fuel pump and remove the harness from weld clip
on the fuel tank.
10. Lower the fuel tank (6).
NOTE: When the fuel tank is lowered from the vehicle,
don’t scratch each hose and tube by around other pars.
Installation
1. Rise the fuel tank into position.
NOTE: Ensure hoses and tubes do not foul on othe
r
component.
2. Connect the pump and sender connector to the
fuel pump and install harness to into the plastic clip
welded to the top of the fuel tank..
NOTE: The connector must be certainly connected
against stopper.
Ensure tank band anchor mates with guide hole on
frame.
3. Install the tank band to fasten bolt.
Torque: 68 N
m (6.9kg
m/50 lb ft)
NOTE: The anchor of the tank band must be certainly
installed to guide hole on frame.
4. Connect the quick connector from the fuel tube to
the fuel pipe and the evapo tube from evapo join
t
connector.
NOTE: Pull off the left checker into the fuel pipe.
NOTE: Refer to “Fuel Tube/Quick Connector Fittings” in
this section when performing any repairs.
5. Install the filler neck to the body by bolt.
6. Install the inner liner of the wheel house on rea
r
side.
7. Remove lifter to support underneath of the fuel
tank.
8. Put back the vehicle.
9. Tigten the filler cap until at least three clicks are
heard.
10. Connect the battery ground cable.