General description
The fuel system includes a fuel tank, a high pressure fuel pump, a fuel filter with a water separator installed in the engine compartment, and fuel supply and return lines and fuel injectors.
The fuel pump rotates at half the crankshaft speed and is belt driven from a sprocket on the rear of the camshaft. Fuel is pumped from the fuel tank through a filter and then distributed under very high pressure to the injectors through separate lines.
The injectors have mechanical spring-loaded valves that open when the fuel pressure in them exceeds a certain value. The fuel is then atomized by the nozzle tip into the vortex chambers above the pistons (direct injection).
The main moment of injection is set mechanically by the position of the pump on the suspension bracket. When the engine is running, the injection timing is mechanically adjusted by the fuel pump and primarily depends on the position of the accelerator and the engine speed.
The engine is stopped by the fuel cut-off valve, which cuts off the fuel supply to the fuel pump.
During a cold start, the idle speed can be increased manually using the cold start accelerator cable, controlled through the handle on the panel in the passenger compartment of the car.
Note: In this Section, the engine code rather than the displacement is used to identify the vehicle - see Engine Codes in Section 1A.
Precautions
Many of the procedures in this Section involve disconnecting fuel lines, which can cause a fuel leak.
Warning: When working on the fuel system, avoid skin contact with diesel fuel - wear protective clothing and gloves.
Fuel injectors operate at extremely high pressure, and the jet of fuel from the tip is capable of penetrating skin. It is recommended that any inspection of the fuel system components be performed by a specialist in diesel fuel injection systems.
Never allow diesel fuel to come into contact with the cooling system hoses. Hoses that have been contaminated with fuel for a long period of time should be replaced. Diesel fuel injection systems are particularly susceptible to contamination, or the ingress of air and water. Keep the fuel system clean to prevent dirt from entering the system. Thoroughly clean the area around the fuel couplers before disconnecting them. Store removed components in sealed containers to prevent contamination. Use only tight (lint-free) fabrics. Avoid using compressed air when cleaning non-removed components.
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