Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 110
6E–44
4JH1 ENGINE DRIVEABILITY AND EMISSIONS
GENERAL DESCRIPTION FOR INJECTION
PUMP
Outline
Instead of the previous face cam type, the radial plunger
distributor type injection pump utilizes a cam ring to
enable fuel injection at high-pressures, marking it
suitable for small, high-speed direct injection diesel
engines. This pump was developed to provide the most
suitable fuel injection quantity and injection timing to
satisfy the demand for engine reliability, driveability, low
smoke, low noise, high output and clear exhaust
emissions.
Characteristic of VP44 Injection System
1. High Pressure Injection
The radial plunger distributor type injection pump is
capable of generating pressure of 100 Mpa
(approximately 1000 Bar) demanded by small, high
speed direct injection diesel engines.
2. High Pressure Atomization of Fuel Injected from
the Nozzle
Through high pressure fuel injection, the fuel is
atomized at high pressure with a high penetrating force
(the fuel droplets penetrate further) and with greater
dispersion and distribution (mixing with air is improved)
and results in better combustion. This contributes to
cleaner emissions.
3. Optimum Fuel Injection
High speed control of fuel injection quantity and fuel
injection timing, is performed by the control unit,
enabling lower fuel cost and high output.
4. Improved Durability
The components used in the pump are very resistant to
high pressure, ensuring improved durability.
5. Improved Engine Matching
As fuel injection is controlled by cylinder selective
adaptation, smooth running is improved.
6. Improved Reliability
As a control unit system with both an engine control
module (ECM) and a pump control unit (PSG) is used,
the control system is extremely reliable.
7. Improved Power Performance
As the control unit controls the optimum fuel injection
quantify corresponding to accelerator position,
increased torque in low accelerator pedal positions is
possible, enabling improved power performance.
8. Decreased Smoke at Acceleration
When the amount of injected fuel is increased, to
increase engine power at acceleration, the excess fuel
usually generates smoke. The VP44 fuel injection pump,
accurately controls fuel injection quantity even in this
range to prevent the generation of smoke without
adversely affecting acceleration.
9. Additional Devices are Unnecessary
Such additional devices as the boost compensator and
the aneroid compensator are unnecessary, as the
control unit compensates, based on signals from each
sensor. This results in less “clutter” injection pump.
10. Self Diagnosis Function
The system includes a self-diagnosis function, which
displays error codes to facilitate the diagnosis of
malfunctions.
(1) Drive Shaft
(2) Feed Pump
(3) Pump Camshaft Speed Sensor
(4) Pump Control Unit (PSG)
(5) Distributor Head
(6) Constant Pressure Valve (CPV) Holder
(7) High Pressure Solenoid Valve
(8) Constant Pressure Valve (CPV)
(9) Timing Control Valve (TCV)
(10) Timer
(11) Radial Plunger High Pressure Pump