2007 ISUZU KB P190 oil temperature

6E-266 Engine Control System (4JH1)
Lack of Power, Sluggishness, Sponginess
Checks Action
DEFINITION:The engine delivers less than expected power. There is little or no increase in speed when partially applying the
accelerator pedal.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Compare the vehicle with a similar unit. Ensure the vehicle has an actual problem.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or
restricted. Replace as necessary.
• Have the tire sizes changed?
• Are excessively heavy loads being carried?
• Inspect for clutch slip.
• Inspect brake drag.
• Inspect for a proper transmission shift pattern and down shift operation (A/T only).
• Inspect the fuel quality (cetane index).
• Inspect the engine oil level and quality.
• Use the scan tool in order to make sure the Vehicle Speed parameter reading
matches the vehicle speedometer.
• Inspect the engine control module (ECM) and fuel injection pump control unit (PCU)
grounds for being clean, tight, and in their proper locations.
• Inspect the scan tool Data List in this section.
• 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 parameter should change linearly from 0% to
100% according to the accelerator pedal operation.

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ISUZU KB P190 2007

6E-268 Engine Control System (4JH1)
Checks Action
Engine Mechanical Check 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).
• Improper mechanical timing
• Improper valve gap
• Broken or weak valve springs
• W orn camshaft lobes
Additional Checks •
Inspect the generator output voltage. Repair if less than 9 volts or more than 16
volts.
• Inspect the EGR system operating correctly.
• Inspect the engine overheat condition. Refer to the Engine Cooling section.
• Inspect the A/C operation.
• Inspect the torque converter clutch (TCC) operation (A/T only).


Hesitation, Sag, Stumble
Checks Action
DEFINITION:The vehicle has a momentary lack of response when pushing down on the accelerator. The condition can occur
at any vehicle speed. The condition is usually most severe when trying to make the vehicle move from a stop. If severe
enough, the condition may cause the engine to stall.
Preliminary Checks • Diagnostic System Check - Engine Controls.
• Compare the vehicle with a similar unit. Ensure the vehicle has an actual problem.
• Remove the air cleaner and check for dirt, or for air ducts being plugged or
restricted. Replace as necessary.
• Inspect for a proper transmission shift pattern and down shift operation.
• Inspect the fuel quality (cetane index).
• Inspect the engine oil level and quality.
• Inspect the scan tool Data List in this section.
• Inspect the engine control module (ECM) and fuel injection pump control unit (PCU)
grounds for being clean, tight, and in their proper locations.
• 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 parameter should change linearly from 0% to
100% according to the accelerator pedal operation.

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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-271
Checks Action
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).
• Inspect for incorrect basic engine parts such as camshaft, cylinder head, pistons,
etc.
• Inspect for any excessive oil entering combustion chamber.
Additional Checks •
Inspect the EGR system operating correctly.
• Inspect other possible causes that can make similar noise such as loose component
parts, bracket, mount and weak clutch damper spring.


Poor Fuel Economy
Checks Action
DEFINITION:Fuel economy, as measured by actual road tests and several tanks of fuel, is noticeably lower than expected.
Also, the economy is noticeably lower than it was on this vehicle at one time, as previously shown by actual road tests.
Preliminary Checks • Remove the air cleaner and check for dirt, or for air ducts being plugged or
restricted. Replace as necessary.
• Inspect the driving habits of the owner.
• Is the A/C ON full time, defroster mode ON?
• Are the tires at the correct pressure?
• Are the tire sizes changed?
• Are excessively heavy loads being carried?
• Is the acceleration too much, too often?
• Inspect for clutch slip.
• Inspect brake drag.
• Inspect dive belt tension.
• Inspect for a proper transmission shift pattern and down shift operation (A/T only).
• Inspect the fuel quality (cetane index).
• Inspect the engine oil level and quality.
• Suggest to the owner to fill the fuel tank and recheck the fuel economy.
• Suggest to the driver to read the Important Facts on Fuel Economy in the Owner
Manual.
• Inspect the odometer is correctly operated.
• 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.
Fuel System Checks Inspect the fuel system for the following conditions. Refer to the Fuel System section.
• Inspect the fuel type and quality.
• Check fuel leak.
Cooling System Checks Inspect the cooling system for the following conditions. Refer to the Cooling System
Section.
• Inspect the engine coolant level.
• Inspect the engine thermostat for always being open or for the wrong heat range.
• Inspect the engine cooling fan for always being ON.

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ISUZU KB P190 2007

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-273
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.
• Inspect for a worn or damaged turbocharger turbine wheel, shaft or compressor
wheel. Refer to turbocharger inspection in the Engine Mechanical section.
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 Check 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).
• Inspect for incorrect basic engine parts such as camshaft, cylinder head, pistons,
etc.
• Inspect for any excessive oil entering combustion chamber.
• Improper mechanical timing
• Improper valve gap
• Broken or weak valve springs
• W orn camshaft lobes
Additional Checks •
Inspect the EGR system operating correctly.
• Inspect the excessive blow-by gasses.
• Inspect the scan tool Data List in this section.


Excessive Smoke (White Smoke)
Checks Action
DIFINITION:W hite 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.
• Inspect the fuel quality (cetane index).
• Inspect the Service Bulletins for ECM software updates.
Sensor Check 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.
• Inspect the crankshaft position (CKP) sensor is tight and the flywheel circumference
is not damaged.
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-285
Crankshaft Position (CKP) Sensor










RTW 06ESH000101




RTW 66ESH001401
Legend
1. Crankshaft Position (CKP) Sensor
2. Flywheel
3. Slit

The crankshaft position (CKP) sensor is located on top
of the flywheel housing. There are 4 slits spaced 90 °
on the flywheel circumference. The CKP sensor is a
magnetic coil type sensor , which generates an AC
signal voltage based on the crankshaft rotational speed.
The ECM monitors both the CKP sensor and injection
pump camshaft position (CMP) sensor signals to
ensure they correlate with each other.

The following waveform aids to diagnose when there is
an oscilloscope or equivalent.

Engine Coolant Temperature (ECT) Sensor
- Amplitudes of CKP sensor signal (CH1) increase as engine speed increases.
- Each waveform cycle shorten as the engine speed increases.
Terminal: 90 (CH1), 91 (CH2) (+) / GND (-)
Scale: 10V/div 2ms/div
Condition: Approximately 1000RPM

CH1
0V
CH2 0V


RTW 66ESH001501
Legend
1. Engine Coolant Temperature (ECT) Sensor

The engine coolant temperature (ECT) sensor is
installed to the thermostat housing. The ECT sensor is
a variable resistor. The ECT sensor measures the
temperature of the engine coolant. The engine control
module (ECM) supplies 5 volts to the ECT signal circuit
and a ground for the ECT low reference circuit. W hen
the ECT sensor is cold, the sensor resistance is high.
W hen the engine coolant temperature increases, the
sensor resistance decreases. W ith high senso
r
resistance, the ECM detects a high voltage on the ECT
signal circuit. W ith lower sensor resistance, the ECM
detects a lower voltage on the ECT signal circuit.

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ISUZU KB P190 2007

6E-294 Engine Control System (4JH1)
Timing Control Device Description



RTW 66ESH003001
Legend
1. Cam Ring
2. Servo Valve
3. Timer Piston
4. Outlet
5. Feed Pump
6. Inlet
7. Fuel Suction
8. Ball Pin
9. Annular Chamber
10. Hydraulic Stopper
11. Return Passage
12. Timing Control Valve (TCV)

The timing device determines the optimum injection
timing against variations in engine speed. The pressure
of the fuel fed from the feed pump is adjusted in
accordance with speed by the regulating valve. This
delivery pressure acts on the hydraulic stopper's
annular chamber as control pressure. The chambe
r
pressure of the annular chamber is controlled by the
timing control valve (TCV). The timing plunger is
connected to the cam ring by a ball pin. Axial movement
of the timing plunger is transferred to the cam ring in the
form of rotational movement. Movement to the right o
f
the timing plunger (to the spring side) advances
injection timing. The main components are timing
plunger, the TCV and pump camshaft position (CMP)
sensor.

Beginning of Injection Staring






RTW 66ESH003101
The engine control module (ECM) contains
characteristic maps of the beginning of injection,
corresponding to engine operating conditions
(engine load, engine speed and engine coolant
temperature). The fuel injection pump control unit
(PCU) is constantly comparing the set beginning o
f
injection timing and the actual beginning of injection
timing. If there is a difference, the timing control
valve (TCV) is controlled by the duty ratio. (The
actual beginning of injection timing is determined
from the pump camshaft position [CMP] sensor.)


Timing Control Valve




RTW 66ESH003201
Legend
1. Coil
2. From Annular Chamber
3. To Feed Pump
4. Orifice
5. Valve Needle



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ENGINE MECHANICAL (4JK1/4JJ1) 6A-5
EGR system
Based upon data, including water temperature, engine
speeds or engine loads, it is controlled via Engine
Control Module (ECM) to purify exhaust by recycling
part of it.
Its main components include an EGR valve, an EGR
cooler and various sensors.

Connecting rod cap bolt
The angular tightening method of the connecting rod
cap bolt further increases reliability and durability.

Fuel rail-type electronic control injection system
The fuel rail-type electronic control injection system is
composed of a fuel supply pump that sets the target
pressure of high-pressure fuel and supply it, a fuel rail
that measures such high-pressure fuel and a fuel
injector that turns it into a fine spray and injects it. Each
is controlled via ECM based upon various signals, while
injection timing or fuel injection quantity is controlled
under every possible driving condition.

Fuel injector
The fuel injector is a 6-hole nozzle that adjusts fuel
injection quantity or injection timing by opening o
r
closing an electromagnetic valve on the head of the fuel
injector.
ECM corrects the dispersion of fuel injection quantit
y
between fuel injector according to ID code data in
memory. At the replacement of fuel injector, ID code
data should be stored in ECM.


Fuel filter with sedimenter
It is a fuel filter with sedimenter that gets rid of water by
making use of the difference in specific gravity between
light oil and water, which comes with an indicator that
notifies you that it is filled with water.

Preheating system
The preheating system consists of the ECM, the glow
relay, glow plugs and the glow indicator lamp. The
preheating system is operated when the engine coolant
temperature is low, and makes the engine easy to start.

Lubrication system
It is an oil filter with full-flow bypass, which uses a
water-cool oil cooler and oil jet to cool the piston.

Functional inspection
Inspection/adjustment of valve clearance 1. Inspection of valve clearance
• Remove the fuel injector harness assembly.
• Remove the leak off hose.
• Remove the cylinder head cover.
• Rotate the crankshaft to make the No.1
cylinder meet the compression top dead cente
r
(TDC).





RTW 76ASH001301
Legend
1. TDC



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