air filter ISUZU TF SERIES 2004 User Guide

FUEL SYSTEM 6C – 3

MAIN DATA AND SPECIFICATIONS
Description Item
4JA1T (L) 4JA1TC 4JH1TC
Injection pump type
Bosch distributor
VE type Bosch distributor VP44 type
Governor type Mechanical variable
(Half speed oil
pressure) Electrical controled
Timer type Oil pressure Electrical controled
Fuel feed pump type Vane with input shaft
Injection nozzle type Hole type
Number of injection nozzle orifices 5
Injection nozzle orifices
Inside diameter mm (in) 0.19 (0.0075) 0.17 (0.0067) 0.21 (0.0083)
19.1 (195) 19.0 (194) 19.5 (199) Injection nozzle designed operating
pressure MPa (kg/cm2) 1st
2nd 25.0 (255) 33.5 (328) 33.8 (331)
Main fuel filter type Disposable cartridge paper element


Precautions
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 fo
r
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.

NOTE:
Injection nozzle adjustment is possible only on the 4JA1L
engine.

FUEL SYSTEM 6C – 5


FUEL FILTER AND WATER SEPARATOR
As the inside of the injection pump is lubricated by the fuel which it is pumping, the fuel must be perfectly clean. The
fuel filter and the water separator remove water particles and other foreign material from the fuel before it reaches
the injection pump.
The water separator has an internal float. When the float reaches the specified level, a warning light comes on to
remind you to drain the water from the water separator.
A diaphragm type priming pump is installed at the top of the fuel filter. It is used during the air bleeding procedures.

(Except EURO III model)


RTW36CLF000701

6E–12 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
324
1
(1) Throttle Position Sensor (TPS)
(2) Pump Control Unit (PSG)(3) Injection Pump Assembly
(4) Fuel Filter (Ex cept Euro 3)
213
(1) Mass Air Flow (MAF) & Intake Air Temperature
(IAT) Sensor Assembly
(2) EGR EVRV(3) Air Cleaner Case

6E–82 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
GENERAL SERVICE INFORMATION
Serviceability Issues
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold
sensor or switch is installed, it makes a wrong diagnosis
and turns on the check engine lamp.
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the check
engine lamp.
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the check
engine lamp to turn on if the vehicle is not maintained
properly. Restricted oil filters, fuel filters, and crankcase
deposits due to lack of oil changes or improper oil
viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a “non-vehicle
fault”, but with the sensitivity of OBD diagnostics,
vehicle maintenance schedules must be more closely
followed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any
diagnostic procedure or diagnosing the cause of an
emission test failure. This can often lead to repairing a
problem without further steps. Use the following
guidelines when performing a visual/physical
inspection:
Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.
Inspect hoses that are difficult to see behind other
components.
Inspect all wires in the engine compartment for
proper connections, burned or chafed spots, pinched
wires, contact with sharp edges or contact with hot
exhaust manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain
when performing diagnostic procedures could result in
an incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to
effectively use this section of the Service Manual.
ON-BOARD DIAGNOSTIC (OBD)
On-Board Diagnostic (Self Diagnosis
System) Tests
A diagnostic test is a series of steps, the result of which
is a pass or fail reported to the diagnostic ex ecutive.
When a diagnostic test reports a pass result, the
diagnostic ex ecutive records the following data:
The diagnostic test has been completed since the
last ignition cycle.
The diagnostic test has passed during the current
ignition cycle.
The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the
diagnostic ex ecutive records the following data:
The diagnostic test has been completed since the
last ignition cycle.
The fault identified by the diagnostic test is currently
active.
The fault has been active during this ignition cycle.
The operating conditions at the time of the failure.
The Diagnostic Executive
The Diagnostic Executive is a unique segment of
software which is designed to coordinate and prioritize
the diagnostic procedures as well as define the protocol
for recording and displaying their results. The main
responsibilities of the Diagnostic Ex ecutive are listed as
follow s:
Commanding the check engine lamp on and off
DTC logging and clearing
Current status information on each diagnostic
Diagnostic Information
The diagnostic charts and functional checks are
designed to locate a faulty circuit or component through
a process of logical decisions. The charts are prepared
with the requirement that the vehicle functioned
correctly at the time of assembly and that there are not
multiple faults present.
There is a continuous self-diagnosis on certain control
functions. This diagnostic capability is complemented
by the diagnostic procedures contained in this manual.
The language of communicating the source of the
malfunction is a system of diagnostic trouble codes.
When a malfunction is detected by the control module, a
diagnostic trouble code is set and the check engine
lamp is illuminated.
Check Engine Lamp
The check engine lamp looks the same as the check
engine lamp you are already familiar with, the “Check
Engine” lamp.
Basically, the check engine lamp is turned on when the

6E–116 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
52 P0215 A ON Fuel Cutoff Solenoid Valve
Malfunction1. Ignition key switch off.
2. Engine speed is below
1 5 0 0 r p m .
3. Vehicle speed is below
1 . 5 k m / h .
4. PSG (pump control unit)
recognizes MAB (fuel
cutoff solenoid valve)
signal from the ECM, but
the MAB could not
operate. 1. MAB (fuel cutoff solenoid
v a l v e ) i s o p e r a t e d .
2. Desired injection quantity
becomes 0mg/strk.No recovery until condition
match in the next ignition key
cycle.1. PSG (pump control unit)
m a l f u n c t i o n .
2. MAB (fuel cutoff solenoid
valve) malfunction.
——
B ON Fuel Cutoff Solenoid Valve
Circuit High InputECM does not command
MAB (fuel cutoff solenoid
valve) signal to the PSG
(pump control unit), but PSG
detected MAB signal line
circuit is high level.Engine does not start. No recovery. 1. MAB (fuel cutoff solenoid
valve) signal circuit short
t o v o l t a g e c i r c u i t .
2. PSG (pump control unit)
malfunction.105 —
C ON Fuel Cutoff Solenoid Valve
Always Active1. Ignition key switch off.
2. Engine speed is below
1 5 0 0 r p m .
3. Vehicle speed is below
1 . 5 k m / h .
4. PSG (pump control unit)
does not recognize MAB
(fuel cutoff solenoid
valve) signal from the
ECM. 1. MAB (fuel cutoff solenoid
v a l v e ) i s o p e r a t e d .
2. Desired injection quantity
becomes 0mg/strk.No recovery until condition
match in the next ignition key
cycle.1. MAB (fuel cutoff solenoid
valve) signal circuit open
or short to ground circuit.
2. PSG (pump control unit)
malfunction.
105 —
D ON Fuel Cutoff Solenoid Valve
Malfunction1. Ignition key switch off.
2. CAN controller does not
operate Bus-off.N o f a i l - s a f e f u n c t i o n . 1 . E C M m a l f u n c t i o n .
2. PSG (pump control unit)
malfunction.——
54 P0216 A ON Injection Timing Control
Circuit Malfunction1. Engine speed is more
t h a n 7 0 0 r p m .
2. Fuel injection quantity is
more than 4mg/stk.
3. Deviation of actual
injection timing and
desired injection timing is
more than +3 deg. CA or
-6 deg. CA for 8 seconds.Fuel injection quantity is
reduced.Deviation of actual injection
timing and desired injection
timing is more than +3 deg.
CA or -6 deg. CA for 8
seconds.1. Timing control valve
m a l f u n c t i o n .
2 . T i m e r p i s t o n s t i c k i n g .
3. Pump camshaft speed
sensor malfunction.——
B ON Injection Timing Control
Circuit Malfunction 1. Engine speed is more
t h a n 2 0 1 4 r p m .
2. Fluctuation of actual
injection timing is more
than +-5.2 deg. CA.1. Engine speed is more
than 2014rpm.
2. Fluctuation of actual
injection timing is more
than +-5.2 deg. CA.1. Insufficient air bleeding of
f u e l l i n e .
2. Fuel filter clogging.
3. Timing control valve
m a l f u n c t i o n .
4. Pump camshaft speed
sensor malfunction. —— Flash
CodeCodeSymptom
CodeMILDTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure PartsRelated
ECM Pin
No.Related
Multiple
DTC4JA1-TC
(MT)4JH1-TC
(MT)4JH1-TC
(AT)

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–179
Circuit Description
The ECM is calculates an injection quantity and an
injection timing using the various sensors (crankshaft
position sensor, camshaft position sensor, engine
coolant temperature sensor, etc.). The timing control
valve (TCV) operation performs an injection timing
decision.
The TCV performs as a variable throttle, using the rapid
opening and closing cycle of the valve needle in the
TCV.
The TCV is assembled in the injection pump. The signal
of desired injection timing and actual injection timing are
ex changed via the CAN-bus between the PSG and
ECM.
If the timer position is out of tolerance (deviation or
fluctuation), DTC P0216 will be stored.
Diagnostic Aids
An intermittent may be caused by the following:
Poor connections.
Misrouted harness.
Rubbed through wire insulation.
Broken wire inside the insulation.
Insufficient air bleeding of fuel line.
Low fuel quantity in the fuel tank.
Check for the following conditions:
Insufficient air bleeding of fuel line inside, clogged
fuel filter or pinched fuel pipe/hose may cause the
DTC store or improper engine performance.Air bleeding procedure:
1.Operate the priming pump until strong resistance is
felt.
2.Wait 1 minute, and operate the priming pump until
strong resistance is felt.
3.Wait 1 minute, and operate the priming pump until
strong resistance is felt.
4.Turn the ignition switch to the "ON" position. Wait
until the glow indicator lamp turns off.
5.Turn the ignition switch to the "START" position and
crank the engine until it starts.
6.If the engine does not start, repeat Step 3 - 5.
7.Allow the engine to idle for 3 minutes to bleed air
completely form the fuel system and check for fuel
leakage.
Poor connection at ECM and PSG-Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and poor terminal to wire connection.
Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe
the "Actual Injection Start" display on the Tech2 while
moving connectors and wiring harness related to the
sensor.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–181
5 V i s u a l l y / p h y s i c a l l y i n s p e c t f o r t h e f o l l o w i n g c o n d i t i o n s .
Restrict fuel supply system. Check for a pinched
fuel ho se /pi pe.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
f u e l.
If a problem is found, repair as necessary.
Was a problem found? - Verify repair Go to Step 6
6 Replace the fuel fi lt er.
Was the problem solved? - Verify repair Go to Step 7
7 Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions.

Objects blocking at the gauze filter. Check for a
condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
ex tended maintenance interval.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
f u e l.
If a problem is found, repair as necessary.
Was the problem found?
-Replace the
eye bolt with
gauze filter and
verify repair Go to Step 8
8 Is the ECM programmed with the latest software
release? If
not, download the latest software to the ECM using
the "SPS (Service Programming System)".
Was the problem solved? - Verify repair Go to Step 9
9 Substitute a known good ECM and recheck.
Was the problem solved?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 "Immobilizer System-ECM replacement" for
the ECM/Immobilizer linking procedure. - Go to Step 10Go to Step 11 Step Action Value(s) Yes No

6E–362 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
ENGINE CRANKS BUT WILL NOT RUN
DEFINITIONS: Engine cranks, but will not run. (The engine never start.)
NOTE: The vehicle with immobilizer system, this system may be activated. Check the immobilizer system diagnosis.
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?—Verify repair Go to Step 3
3 Was a visually/physical check performed?
—Go to Step 4Go to Visual /
physical Check
4 Is the fuel amount enough?
—Go to Step 5Add fuel to the
tank
5 Is the customer using the incorrect fuel type? Diesel fuel
onlyReplace with
diesel fuel Go to Step 6
6 Check the “ECM” fuse (10A) and “Engine” fuse (15A).
If the fuse is burnt out, repair as necessary.
Was the problem found?—Verify repair Go to Step 7
7 Visually/physically inspect for the following conditions.
Restrict air intake system. Check for a restricted air
filter element, or foreign objects blocking the air
intake system
Check for objects blocking or ex cessive deposits in
the throttle bore and on the throttle plate
Check for a condition that causes a large vacuum
leak, such as an incorrectly installed or faulty
crankcase ventilation hose.
Restrict air intake system at the turbocharger.
Check for objects blocking the turbocharger
compressor wheel or turbine shaft sticking.
If a problem is found, repair as necessary.
Was a problem found?—Verify repair Go to Step 8
8 Check the ECM & PSG grounds to verify that they are
clean and tight. Refer to the ECM wiring diagrams.
Was a problem found?—Verify repair Go to Step 9
9 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Monitor the “Neutral Switch” in the data display.
Does the Tech 2 indicate correct “Neutral Switch”
status depending on any shift positions?
If a problem is found, repair as necessary.
Was the problem found?—Verify repair Go to Step 10

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–363
10 Remove the CKP sensor from the flywheel housing
and check for the following conditions.
Objects sticking the CKP sensor.
Objects sticking the CKP sensor pulser.
If a problem is found, repair as necessary.
Was the problem found? —Verify repair Go to Step 11
11 Check the CKP sensor harness for the following
conditions.
Check for poor connector connection.
Check for misrouted harness.
Check for any accessory parts which may cause
electric interference.
If a problem is found, repair as necessary.
Was a problem found? —Verify repair Go to Step 12
12 Substitute a known good CKP sensor and recheck.
Was the problem solved?—Go to Step 13Go to Step 14
13 Replace the CKP sensor.
Is the action complete?—Veri fy repai r—
14 Check the ex haust system for a possible restriction.
Damaged or collapsed pipes or catalytic converter.
Internal muffler failure.
If a problem is found, repair as necessary.
Was a problem found?—Verify repair Go to Step 16
15 Visually/physically inspect for the following conditions.
Restrict fuel supply system. Check for a pinched
fuel hose/pipe.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
fuel.
If a problem is found, repair as necessary.
Was a problem found?—Verify repair Go to Step 17
16 Replace the fuel filter.
Was the problem solved?—Verify repair Go to Step 18 Step Action Value(s) Yes No

6E–364 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
17 Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions.
Objects blocking at the gauze filter. Check for a
condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
ex tended maintenance interval.
Check for a condition that causes fuel wax ing or
icing, such as the customer is using an incorrect
fuel type in winter season or water mix ed with the
fuel.
If a problem is found, repair as necessary.
Was the problem found?
—Replace the
eye bolt with
gauze filter and
verify repair Go to Step 18
18 Check the engine compression pressure for each
cylinders.
If a problem is found, repair as necessary.
Was the problem found?
More than 2.1
Mpa (21.0 kg/
cm
2) Verify repair Go to Step 19
19 If the injection pump was replaced, are the timing
gears or injection pump correctly installed?
—Go to Step 20Repair as
necessary Step Action Value(s) Yes No