engine ISUZU KB P190 2007 Workshop Repair Manual

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






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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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ISUZU KB P190 2007

Engine Control System (4JH1) 6E-295
The timing control valve (TCV) acts as a variable
throttle, using the rapid opening and closing (cycling)
of the valve needle in the TCV.
At normal operation,
the TCV controls the pressure acting on the annula
r
chamber so that the hydraulic stopper cam move to
any position, from the retard position to the advance
position. At this time, the duty ratio is set by the fuel
injection pump control unit (PCU).

When control current flows to the TCV coil, the valve
needle opens and the fuel annular chamber flows
through the orifice to the feed pump inlet.
Consequently, the pressure of the annular chambe
r
decreases and the hydraulic stopper is moved to the
retard side.

When control current to the TCV coil is cut, the valve
needle closes and the return passage is closed.
Consequently, the pressure of the annular chambe
r
increases and the hydraulic stopper is moved to the
advance side.

Pump Camshaft Position (CMP) Sensor



RTW 66ESH003301
Legend
1. Pump Camshaft Position (CMP) Sensor
2. Flexible Connecting Harness
3. Drive Shaft
4. Pump Camshaft Position (CMP) Sensor Retaining Ring
5. Sensor W heel


W hen the drive shaft rotates, the pump camshaft
position (CMP) sensor receives signal form the senso
r
wheel, and an electric pulse is sent through the flexible
connecting harness to the fuel injection pump control
unit (PCU). From these signals the PCU can determine
the average pump speed and the momentary pump
speed. The pump CMP sensor is mounted to the cam
ring. Thus, the relationship between the cam ring and
the pump CMP sensor signal is constant. The pump
CMP sensor signal is utilized for the following purposes:
• To determine the momentary angular position o
f
the cam ring.
• To calculate the actual speed of the fuel injection
pump.
• To determine the actual timing plunger position.




RTW 66ESH003401Legend
1. Pump Camshaft Position (CMP) Sensor Signal
2. Crankshaft Position (CKP) Sensor Signal
3. Fuel Injection Solenoid Valve Control Pulse
4. Fuel Injection Solenoid Needle Valve Lift
5. Cam Lift (Cam Profile)
6. Pulse Count
7. Fuel Injection Solenoid Valve Close
8. Fuel Injection Solenoid Valve Open
9. Start of Pressure Delivery
10. End of Pressure Delivery
11. Pressure Delivery Angle
12. Effective Stroke






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ISUZU KB P190 2007

6E-296 Engine Control System (4JH1)
• Momentary Cam Ring Angular Position
The momentary angular position of the cam ring is input into the fuel injection PCU as a fuel injection
solenoid valve control signal. From momentar
y
input of angular position for fluctuations in running
conditions, the fuel injection solenoid valve open
and close intervals corresponding to the cam ring's
cam lift can be accurately determined.
• Actual Injection Pump Speed
W hen the crankshaft position (CKP) sensor is faulty, the engine control module (ECM) uses the
pump CMP signal as a replacement signal.
• Actual Timing Plunger Position
The actual timing plunger position can be determined by comparing the CKP sensor signal
with the pump CMP sensor angle. This position is
used for timer control.




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Engine Control System (4JH1) 6E-297
Exhaust Gas Recirculation (EGR) System Description





RTW 66ELF000101
Legend
1. EGR Cooler
2. Engine Coolant Outlet
3. Engine Coolant Inlet
4. EGR Valve


5. ECM
6. MAF & IAT Sensor
7. Intake Throttle Valve
The EGR system recirculates a part of exhaust gas
back into the intake manifold, which results in reducing
nitrogen oxide (NOx) emissions. The EGR control
system uses an electronic control system solenoid valve
and vacuum control EGR valve to ensure both
driveability and low emission. The engine control
module (ECM) controls the EGR flow amount based on
the engine speed, engine coolant temperature, intake
air temperature, barometric pressure and fuel injection
quantity. The ECM controls the EGR valve opening b
y
controlling the EGR solenoid valve drive duty. The mass
air flow (MAF) sensor monitors EGR gas flow amount.
An expected MAF amount should be detected while the
engine running.

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6E-298 Engine Control System (4JH1)
Turbocharger Description






RTW 66EMF000501
Legend
1. Exhaust Gas
2. W astegate Valve
3. Turbine W heel
4. Compressor W heel
5. Air Cleaner


6. Vacuum Pressure Sensor
7. Engine Control Module (ECM)
8. Turbocharger Solenoid Valve
9. Vacuum Pump (ACG)
10. Change Air Cooler (Intercooler)
The turbocharger is used to increase the amount of ai
r
that enters the engine cylinders. This allows a
proportional increase of fuel to be injected into the
cylinders, resulting in increased power output, more
complete combustion of fuel, and increased cooling o
f
the cylinder heads, pistons, valves, and exhaust gas.
This cooling effect helps extend engine life.
Heat energy and pressures in the engine exhaust gas
are utilized to drive the turbine. Exhaust gas is directed
to the turbine housing. The turbine housing acts as a
nozzle to direct the shaft wheel assembly. Since the
compressor wheel is attached directly to the shaft, the
compressor wheel rotates at the same speed as the
turbine wheel. Clean air from the air cleaner is drawn
into the compressor housing and wheel. The air is
compressed and delivered through a crossover pipe to
the engine air intake manifold, then into the cylinders.
The amount of air pressure rise and air volume
delivered to the engine from the compressor outlet is
regulated by a wastegate valve in the exhaust housing.
The position of the wastegate valve is controlled by the
amount of pressure built up on the intake side of the
turbocharger. The diaphragm on the inside of the
wastegate is pressure sensitive, and controls the
position of the valve inside the turbocharger. The
position of the valve will increase or decrease the
amount of boost to the turbocharger.
The charge air cooler also helps the performance of the
diesel. Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressurized
air from the turbocharger then flows forward through the
charge air cooler located in the front of the radiator.
From the charge air cooler, the air flows back into the
intake manifold.
The charge air cooler is a heat exchanger that uses ai
r
flow to dissipate heat from the intake air. As the
turbocharger increases air pressure, the air temperature
increases. Lowering the intake air temperature
increases the engine efficiency and power by packing
more air molecules into the same space.


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Engine Control System (4JH1) 6E-299
Special Tools and Equipment
Special Tools and Equipment
Illustration Tool Number/
Description
Illustration Tool Number/
Description
5-8840-2835-0 /
J-35616-A
Connector Test Adapter Kit
(W ith Test Lamp)
5-8840-0607-0 /
J-34142-B
Test Lamp
5-8840-0285-0 /
J-39200
Digital Multimeter
5-8840-0279-0 /
J-23738-A
Vacuum Pump
Tech2 Kit

Breaker Box

Adapter Harness


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EXHAUST SYSTEM 6F – 7

GENERAL DESCRIPTION
This system controls the formation of NOx emission by recirculating the exhaust gas into the combustion chamber
through the intake manifold.

4JA1T(L):
The two EGR valves are controlled by two Vacuum Switching Valve (VSV) controlled by EGR controller according to
signals from various sensors.
The amount of EGR depends on the number of engine rotations and the opening of the accelerator.







RTW 46ELF001201



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6F – 8 EXHAUST SYSTEM
4JA1TC/4JH1TC
The EGR system engine is controlled by ECM. Refer to “Engine driveability and emissions” section for detail.








RTW 46ELF001101



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EXHAUST SYSTEM 6F – 9
EGR SYSTEM DIAGRAM 4JA1T (L)




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EGR System Operation
Inspect EGR valve motion visually while changing engine RPM under no load condition after warming-up.
• Inspection point (Engine RPM)

RPM Idling 900 ∼ 960 2000 3250
Engine Front Side VSV-1
ON ON ON OFF
Engine Rear Side VSV-2 ON OFF ON OFF

ON means VSV should receive signal to move EGR valve.
OFF means VSV shouldn’t receive signal to move EGR valve.



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6F – 10 EXHAUST SYSTEM
4JA1TC/4JH1TC
The EGR system engine is controlled by ECM. Refer to “Engine driveability and emissions” section for detail.


RTW 46EMF000701

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