Indirect diesel injection

The fuel is drawn directly from the fuel tank by the distributor-type injection pump. Inside the injection pump, the high pressure required for diesel injection (approx. 130 bar) is built up, and the fuel is distributed to the individual cylinders according to the firing order.

At the same time, a governor in the injection pump controls the amount of fuel injected according to the position of the accelerator pedal. The injectors inject the diesel fuel into the precombustion chamber of the respective cylinder at the correct moment. The shape of the precombustion or swirl chamber gives the intake air a specific swirling motion during the compression stroke, so that the injected fuel mixes optimally with the air.

Before the fuel reaches the injection pump, it flows through the fuel filter. Here, contaminants and water are trapped. It is therefore extremely important to drain the fuel filter or replace it according to the maintenance schedule.

The injection pump is maintenance-free. All moving parts of the pump are lubricated with diesel fuel. The injection pump is driven by the crankshaft via the timing belt, which also drives the camshaft.

Since the diesel engine, as a compression-ignition engine, cannot be switched off by interrupting the ignition system's power supply, it has a solenoid valve. When the ignition is switched off, the power supply to the solenoid valve is interrupted and the valve closes the fuel passage.

When the engine is started, the immobilizer releases the solenoid valve and the engine starts. Immobilizer, see page 244.