Isuzu 6HK1/6SD1 Type Engine Service Manual (EN)

For DENSO Authorized ECD Service Dealer Only Diesel Injection Pump No. E-03-02 SERVICE MANUAL Common Rail System for ISUZU 6HK1/6SD1 Type Engine Operation June, 2003 00400018 -1 -1

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Main Elements

GENERAL The common rail system was designed for electronic control of injection quantity, injection tim- ing and injection pressure to obtain optimal operational control. Features • Lower exhaust gas and higher output due to high pressure injection in all usage ranges. • Reduction in noise and exhaust gas due to injection rate control. • Improved performance due to increased flexibility in the injection timing setting. • Independent control of injection pressure in response to engine speed and load. Main Elements 0 Manufacturer Vehicle Model Engine Model Cylinder Configuration Total Displacement (cc) ISUZU Forward 6HK1 Straight 6 7,800 6SD1 9,800 6WG1 15,600

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1.2 System Configuration

1. Outline 1.1 System Outline This system also provides the following functions: • A self-diagnosis and alarm function using computer to diagnose the system’s major components and alert the driver in the event of a problem. • A fail-safe function to stop the engine, depending upon the location of the problem. • A backup function to change the fuel regulation method, thus enabling the vehicle to continue operation. 1.2 System Configuration Divided by function, the system can be classified according to the fuel system and the control system. [1] Fuel System High-pressure fuel that is generated by the supply pump is distributed to the cylinders using a rail.

Electromagnetic valves in the injectors then open and close the nozzle needle valve to con- trol the start and end of fuel injection. Electronic control Solenoid valve to control the needle lift Discharge volume Fuel tank Supply pump Rail Injector Q000080E [2] Control System Based on the signals received from various sensors mounted on the engine and the vehicle, the ECU controls current timing and the duration in which the current is applied to the injectors, thus ensuring an optimal amount of fuel is injected at an optimal time. The control system can be broadly classified according to the following electronic components: sensors, computers, and actuators.

Sensors Computers Actuators (Accelerator opening) Accelerator sensor Injectors NE sensor (Crankshaft position sensor) (Engine speed) ( ) Fuel injection quantity and injection timing control etc. ECU ( ) Cylinder recognition signal TDC sensor (Cylinder recognition sensor) Rail Supply pump Other sensors and switches (Fuel pressure control) Q000081E 1

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1.2 System Configuration

[3] System Configuration (1) Signals from switches ECU Charge-up circuit ACCP Accelerator position sensor STA THW THL Fuel temp. sensor Leak pipe Pressure limiter Starter signal Rail Air cleaner Flow damper Supply pump Water temp. sensor NE sensor TDC sensor Fuel filiter Fuel tank Q000082E 2

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