Diesel Fuel System Components

Fig. 1 Fuel injection nozzle. 1980 all & 1981 exc. Calif.:

Fig. 2 Fuel injection nozzle. 1981 Calif. & all 1983---84:

Fig. 3 Fuel injection pump circuit:

The high pressure, gear driven, rotary fuel injection pump, mounted on top of the engine, which is rotated by the camshaft at camshaft speed, injects a timed, metered amount of fuel to each cylinder.
- The injection pump provides the required timing advance under all operating conditions.

The high pressure fuel delivery pipes from the injection pump to each injection nozzle, Figs. 1 and 2, are of equal length to prevent any difference in fuel injection timing between cylinders.

Engine speed is controlled by a rotary fuel metering valve, Fig. 3.
- When the accelerator is depressed, the throttle cable opens the metering valve and allows more fuel to be delivered to the engine.

A mechanical, diaphragm type, low pressure transfer pump--mounted on the right side of the engine, and driven by a cam on the crankshaft--delivers fuel to the fuel inlet of the high pressure pump, Fig. 3.

The fuel filter is located between the mechanical fuel pump--low pressure pump--and the injection pump.

The fuel tank at the rear of the vehicle is connected by fuel pipes to the mechanical fuel pump. Excess fuel returns from the fuel injection pump and injection nozzles to the fuel tank through pipes and hoses.

Injection nozzles used on 1981 California models and all 1983---84 models do not use a fuel return line.