2007 ISUZU KB P190 Fuel line

6E-272 Engine Control System (4JH1)
Checks Action
Air Intake System Checks Inspect the air intake system for the following conditions.
• Inspect the air cleaner and air intake ducts for a restriction, holes, or leaks.
• Inspect for a restriction or leak in the intercooler.
• Inspect for a restriction in the turbocharger inlet duct.
• Inspect for a restriction or deposit in the intake throttle bore.
• Inspect for a restriction or leak in the intake manifold.
• Inspect for a restriction or damage at MAF sensor.
Exhaust System Checks Inspect the exhaust system for a possible restriction. Refer to the Exhaust System
section.
• Inspect for a restriction in the catalytic converter or exhaust pipes.
Engine Mechanical Checks Inspect the engine mechanical for the following conditions. Refer to the Engine
Mechanical section.
• Inspect for poor cylinder compression. Proper compression is more than 2100 kPa
(309 psi).


Excessive Smoke (Black Smoke)
Checks Action
DEFINITION:Black smoke under load, idle or start up hot or cold.
Preliminary Check •
Ensure the vehicle has an actual problem.
• Inspect the engine control module (ECM) and fuel injection pump control unit (PCU)
grounds for being clean, tight, and in their proper locations.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or
restricted. Replace as necessary.
• Inspect the fuel quality (cetane index).
• Inspect the engine oil level and quality.
• Inspect the Service Bulletins for ECM software updates.
Sensor Checks Inspect the engine control sensors for the following conditions. Refer to the scan tool
Data List in this section.
• Use the scan tool to compare the Engine Coolant Temperature (ECT) with the Intake
Air Temperature (IAT) and Fuel Temperature (FT) on a cold engine condition. If the
difference among temperature reading is more than 5°C (9°F) on a cold engine,
check for high resistance on the low reference circuit and signal circuit or for a
skewed sensor.
Notice: The mass air flow (MAF) sensor is heated and as a result the IAT sensor may
indicate a higher than normal intake air temperature if the ignition switch is being ON.
FT sensor is internal to the PCU and it is part of the fuel injection pump assembly.
• Use the scan tool to compare the MAF Sensor parameter with the Desired MAF
parameter. Start the engine and warm up (allow engine coolant temperature to reach
at least 60°C [140°F]). The MAF Sensor parameter must follow the Desired MAF
parameter within 100 mg/strk. If not, inspect the air intake system, EGR system
components and contaminated, skewed or slow MAF sensor.
• Use the scan tool to observe the Accelerator Pedal Position Accelerator Pedal
Position. Accelerator Pedal Position indicating angle parameter should change
linearly from 0% to 100% according to the accelerator pedal operation.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to the Fuel System section.
• Inspect the fuel injection nozzle(s) for proper splay condition or operating pressure.
Notice: Only first stage of operating pressure can be checked.
• Inspect the timing device operating correctly. Observe the Actual Injection Timing
parameter with the scan tool while running the engine. The Actual Injection Timing
parameter must follow the Desired Injection Timing within 2°CA on each engine
speed. Engine idle > around 2000 RPM> around 3000 RPM. If not, inspect the fuel
system restriction, air in the fuel or fuel injection pump operation.

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-283
Description And Operation
Engine Control Module (ECM) Description



RTW 66ESH001201
The engine control module (ECM) is designed to
withstand normal current draws associated with vehicle
operation. Avoid overloading any circuit. W hen testing
for opens and shorts, do not ground or apply voltage to
any of the ECM circuits unless instructed to do so. In
some cases, these circuits should only be tested using
a digital multi meter (DMM). The ECM should remain
connected to the ECM harness.
The ECM is located on the floor panel. The ECM mainl
y
controls the following.
• The fuel system control
• The exhaust gas recirculation (EGR) system
control
• The preheating (glow) system control
• The A/C compressor control
• On-board diagnostics for engine control
The ECM constantly observes the information from
various sensor s. The ECM controls the systems that
affect vehicle performance. The ECM performs the
diagnostic function of the system. The ECM can
recognize operational problems, alert the driver through
the malfunction indicator lamp (MIL), and store
diagnostic trouble codes (DTCs). DTCs identify the
system faults to aid the technician in making repairs.





ECM Voltage Description
The ECM supplies a buffered voltage to various
switches and sensor s. The ECM can do this because
resistance in the ECM is so high in value that a test
lamp may not illuminate when connected to the circuit.
An ordinary shop voltmeter may not give an accurate
reading because the voltmeter input impedance is too
low. Use a 10-megaohm input impedance DMM, to
ensure accurate voltage readings. The input and/o
r
output devices in the ECM include analog-to-digital
converters, signal buffers, counters, and special drivers.
The ECM controls most components with electronic
switches which complete a ground circuit when turned
ON.
Aftermarket Electrical and Vacuum Equipment
Aftermarket or add-on electrical and vacuum equipment
is defined as any equipment which connects to the
vehicle's electrical or vacuum systems that is installed
on a vehicle after the vehicle leaves the factory. No
allowances have been made in the vehicle design fo
r
this type of equipment. No add-on vacuum equipment
should be added to this vehicle. Add-on electrical
equipment must only be connected to the vehicle's
electrical system at the battery power and ground. Add-
on electrical equipment, even when installed to these
guidelines, may still cause the powertrain system to
malfunction. This may also include equipment not
connected to the vehicle electrical system such as
portable telephones and audios. Therefore, the first
step in diagnosing any powertrain fault is to eliminate all
aftermarket electrical equipment from the vehicle. Afte
r
this is done, if the fault still exists, the fault may be
diagnosed in the normal manner.
Electrostatic Discharge Damage
Electronic components used in the ECM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused b
y
electrostatic discharge. By comparison, as much as
4,000 volts may be needed for a person to feel even the
zap of a static discharge. There are several ways for a
person to become statically charged. The most
common methods of charging are by friction and
induction. •
An example of charging by friction is a person
sliding across a vehicle seat.


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ISUZU KB P190 2007

6E-284 Engine Control System (4JH1)
Important:
To prevent possible electrostatic discharge damage,
follow these guidelines: • Do not touch the ECM connector pins or soldered
components on the ECM circuit board.
• Do not open the replacement part package until
the part is ready to be installed.
• Before removing the part from the package,
ground the package to a known good ground on
the vehicle.
• If the part has been handled while sliding across
the seat, while sitting down from a standing
position, or while walking a distance, touch a
known good ground before installing the part.
• Charge by induction occurs when a person with
well insulated shoes stands near a highly charged
object and momentarily touches ground. Charges
of the same polarity are drained off leaving the
person highly charged with opposite polarity.
Malfunction Indicator Lamp (MIL) Operation
The malfunction indicator lamp (MIL) is located in the
instrument panel cluster (IPC). The MIL will display the
following symbols when commanded ON:



RTW 76ESH004001
The MIL indicates that an emission or performance
related fault has occurred and vehicle service is
required. The following is a list of the modes o
f
operation for the MIL: • The MIL illuminates for approximately 2 seconds
when the ignition switch is turned ON, with the
engine OFF. This is a bulb test to ensure the MIL
is able to illuminate.

•
The MIL remains illuminated after the engine is
started if the ECM detects a fault. A DTC is stored
any time the ECM illuminates the MIL due to an
emission or performance related fault.

Engine Control Component Description
Accelerator Pedal Position (APP) Sensor & Idle
Switch






RTW 66ESH001301
The accelerator pedal position (APP) sensor is mounted
on the throttle assembly. The engine control module
(ECM) uses the APP sensor s to determine the amount
of acceleration or deceleration desired by the person
driving the vehicle via the fuel injection control.
The idle switch is also mounted on the intake throttle
assembly. The idle switch is part of the APP senso
r
assembly. The idle switch is a normally closed type
switch. W hen the accelerator pedal is released, the idle
switch signal to the ECM is low voltage.








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ENGINE MECHANICAL (4JK1/4JJ1) 6A-3
ISUZU DIESEL ENGINE (4JK1/4JJ1)
Service Precautions
Matters that require attention in terms of
maintenance
To prevent damage to the engine and ensure reliabilit
y
of its performance, pay attention to the following in
maintaining the engine:
• W hen lifting up or supporting the engine, do not
apply a jack on the oil pan.
W hen taking down the engine on the ground, do not make the bearing surface of the oil pan touch
the ground directly. Use a wooden frame, fo
r
example, to support the engine with the engine
foot and the flywheel housing.
Because there is only a small clearance between the oil pan and the oil pump strainer, it can
damage the oil pan and the oil strainer.
• W hen the air duct or air cleaner is removed, cove
r
the air intake opening to prevent foreign matter
from getting into the cylinder. If it gets
contaminated, it can considerably damage the
cylinder and others while the engine is operating.
• W hen maintaining the engine, never fail to remove
the battery earth cable. If not, it may damage the
wire harness or electrical parts. If you need
electricity on for the purpose of inspection, fo
r
instance, watch out for short circuits and others.
•
Apply engine oil to the sliding contact surfaces of
the engine before reassembling it. This ensures
adequate lubrication when the engine is first
started.
• W hen valve train parts, pistons, piston rings,
connecting rods, connecting rod bearings o
r
crankshaft journal bearings are removed, put them
in order and keep them.
• W hen installing them, put them back in the same
location they were removed from.
• Gaskets, oil seals, O-rings, etc. must be replaced
with new ones when the engine is reassembled.
•
As for parts where a liquid gasket is used, remove
an old liquid gasket completely and clean it up
thoroughly so that no oil, water or dust is clinging
to them. Then, apply the designated liquid gasket
to each place anew before assembly.

• Surfaces covered with liquid gasket must be
assembled within 5 minutes of gasket application.
If more than 5 minutes has elapsed, remove the
existing liquid gasket and apply a new liquid
gasket.
• W hen assembling or installing parts, fasten them
with the prescribed tightening torque so that the
y
are installed properly.

Matters that require attention in specifically dealing
with this engine.
Holes or clearances in the fuel system, which serve as
a passage of fuel, including the inside of the injector,
are made with extreme precision. For this reason, the
y
are highly sensitive to foreign matter and, if it gets in, it
can lead to an accident on the road, for instance; thus,
make sure that foreign matter is prevented from getting
in.

W hen servicing the fuel system, every precaution must
be taken to prevent the entry of foreign material into the
system.
• Before beginning the service procedure, wash the
fuel line and the surrounding area.
• Perform the service procedures with clean hands.
Do not wear work gloves.
• Immediately after removing the fuel hose and/o
r
fuel pipe, carefully tape vinyl bags over the
exposed ends of the hose or pipe.
• If parts are to be replaced (fuel hose, fuel pipe,
etc.) do not open the new part packaging until
installation.

Work procedure
• The fuel opening must be quickly sealed when
removing the fuel pipe, injection pipe, fuel injector,
fuel supply pump, and fuel rail.
• The eyebolts and gasket must be stored in a clean
parts box with a lid to prevent adhesion of foreign
matter.
• Fuel leakage could cause fires. Therefore, afte
r
finishing the work, wipe off the fuel that has leaked
out and make sure there is no fuel leakage afte
r
starting the engine.


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ISUZU KB P190 2007

ENGINE MECHANICAL (4JK1/4JJ1) 6A-13
Main Data and specifications
Item Engine model 4JK1 Engine model 4JJ1
Type Diesel/4-cycle/water cooling-type in-line DOHC
Combustion chamber type Direct injection type
Cylinder liner type Liner less
Number of cylinders -cylinder
bore × strokes mm (in) 4-95.4 (3.76) × 87.4 (3.44) 4-95.4(3.76) × 104.9(4.13)
Displacement
cc (cu.in) 2499 (152) 2999 (183)
Compression ratio 18.3 17.5
Compression pressure MPa (psi)/rpm 3 (435)/200
Idling speed rpm 700 ± 25
Valve clearance Intake 0.15 (0.006) (cold)
mm (in) Exhaust 0.15 (0.006) (cold)
Ignition type Compressed ignition
Injection order 1 - 3 - 4 - 2
Lubricating system
Lubricating type Pressure delivery type
Oil pump type Gear type
Volume of lubricating oil L (qts) 8.0 (8.5)
Oil filter type Full flow filter (cartridge type)
Oil cooling type Built-in-type, water cooling
Cooling system
Cooling type W ater cooling type
Radiator type Corrugated fin (pressure type)
W ater pump type Centrifugal, belt drive type
Thermostat type W ax-type units
Thermostat valve-opening temperature °C ( °F) 85 (185)
Volume of coolant L (qts) M/T8.7 (9.2) A/T 8.6 (9.1) (incl. radiator)
Fuel system
Injection pump type Fuel supply pump fuel rail type
Fuel injector type Electronic control injector
6-hole
Fuel pump type Into the fuel tank type
Charging system
Generator type AC type
Power output V-A 12 - 90

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6C-2 FUEL SYSTEM (4JK1/4JJ1)
Fuel System
Service Precautions
Parts of the fuel system such as the internal part of the
fuel injector, and holes and clearances that form
passages for fuel are finished to a very high degree o
f
accuracy. They are therefore highly sensitive to foreign
matter and the entry of foreign matter could cause
damage to the fuel passage. Therefore, effective
measures should be taken to prevent the entry o
f
foreign matter.
If a water removal agent is used in the fuel then it will
absorb moisture in the light oil and may cause rust.
Therefore, do not use a water removal agent in the fuel
tank.
W hen servicing the fuel system, every precaution must
be taken to prevent the entry of foreign material into the
system.
• Before beginning the service procedure, wash the
fuel line and the surrounding area.
• Perform the service procedures with clean hands.
Do not wear work gloves.
• Immediately after removing the fuel hose and/o
r
fuel pipe, carefully tape vinyl bags over the
exposed ends of the hose or pipe.
• If parts are to be replaced (fuel hose, fuel pipe,
etc.) do not open the new part packaging until
installation.
Discard gaskets and O-rings and replace them with ne
w
ones.

Work procedure
•
The fuel opening must be quickly sealed when
removing the fuel pipe, injection pipe, fuel injector,
fuel supply pump, and fuel rail.
• The eyebolts and gasket must be stored in a clean
parts box with a lid to prevent adhesion of foreign
matter.
• Fuel leakage could cause fires. Therefore, afte
r
finishing the work, wipe off the fuel that has leaked
out and make sure there is no fuel leakage afte
r
starting the engine.

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ISUZU KB P190 2007

6C-8 FUEL SYSTEM (4JK1/4JJ1)
Trouble Shooting
Problems with starting
Condition Possible Cause Correction
Problems with starting Fuel tank is empty Fill the tank.
Air has entered the fuel system. Bleed the air.
Fuel line or fuel cooler is clogged or
damaged. Connection to the fuel line
is loose. Repair or replace the fuel line and
fuel cooler. Re-tighten the
connection.
Fuel filter element is clogged. Replace the cartridge.
Fault in the feed pump Replace the fuel supply pump.
Regulating valve is open. Replace
Sticking of the fuel injector Replace the fuel injector.
Defective engine control system Diagnose the engine control system.

Hunting during idling
Condition Possible Cause Correction
Hunting during idling Air has entered the fuel system. Bleed air from the fuel system.
Leakage or clogging of the fuel
system Repair or replace the fuel system.

Drops of water have entered the fuel
system. Replace the fuel.

Fuel filter element is clogged. Replace the fuel filter element
(cartridge).
Sticking of the fuel injector Replace the fuel injector.
Defective engine control system Diagnose the engine control system.

Insufficient horsepower
Condition Possible Cause Correction
Insufficient horsepower Air has entered the fuel system. Bleed air from the fuel system.
Leakage or clogging of the fuel
system Repair or replace the fuel system.

W ater mixes in the fuel system Replace the fuel.
Fuel filter element is clogged. Replace the element or the
cartridge.
Sticking of the fuel injector Replace the fuel injector.
Defective engine control system Diagnose the engine control system.

Maximum engine speed is too low
Condition Possible Cause Correction
Maximum engine speed is too low Fuel line, fuel cooler is clogged or
damaged. Repair or replace the fuel line, fuel
cooler.
Defective engine control system Diagnose the engine control system.


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ISUZU KB P190 2007

6C-10 FUEL SYSTEM (4JK1/4JJ1)
Fuel System Check
Description
Conforms to a fuel leak. Engine acceleration raises fuel
pressure and which increases the leak.
Leak could be in the following pipes and locations.
• Between injectors and fuel rail.
• Between fuel rail and fuel supply pump.
• Between fuel supply pump and fuel filter.
• Between fuel filter and fuel tank.
• Between pressure limiter and fuel cooler.
• Between fuel cooler and fuel tank.
• Between injector over flow and leak off pipe.
Diagnostic Aids
Check the following items.
• Air in the fuel line
• Clogged fuel filter
• Fuel pipe malfunction (Crushing, breakage,
clogging, disconnection, etc.)
• Fuel cooler malfunction (Crushing, breakage,
clogging, disconnection, etc.)
• Fuel tank malfunction
• Injector malfunction
• Fuel supply pump malfunction
• Pressure limiter malfunction
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for poor connections or a
damaged harness.
Inspect the ECM harness and connector for imprope
r
mating, broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
ECU may set a DTC, if there is adequate air in fuel line.


Schematic Reference: Engine Controls Schematics
Step Action Value(s) Yes No
1 Check the fuel quantity. W as a problem found? 

Go to Step 2 Add fuel and
Go to Step 2
2 Check the fuel quality.
1. Discharge the fuel from fuel tank
2. Replenish the tank with specified fuel
3. Bleed the air from the fuel system
4. Start the engine
Could the engine be started? 

Go to Step 7 Go to Step 3
3 Bleed the air from fuel system. Refer to Fuel
System Air Bleeding in this section.
Is the action complete? 

Go to Step 4 

4 Check the main fuel filter for clogging.
Clean, repair, or replace as required.
Notice: Replacement of a fuel filter is checking
to a dealer.
Is the action complete? 

Go to Step 5 

5 Check the fuel line and fuel cooler for damage
and leakage.
Clean, repair, or replace as required.
• Crushed areas
• Breakage
• Cracks
• Loose connections
Is the action complete? 

Go to Step 6 


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ISUZU KB P190 2007