In contrast to the injection system, there is very little to report about the actual engine, apart from the vortex chamber process already discussed. Except for the cylinder head, it is identical to the bucket tappet motor of the gasoline engine, which is inclined backwards by 15°, and is even mounted on the same assembly line, apart from a small detour because of the cylinder head. However, instead of the ignition distributor, it has a vacuum pump for the brake booster.

All that remains is the distributor injection pump. It's been around for a long time. It also supplies all existing cylinders after the injection sequence with one revolution, but its pistons work radially to the main shaft and are actuated by cam rings, which enables higher pressures. The axial pump of the first Golf Diesel from Bosch only had a maximum injection pressure of around 450 bar.

For this purpose, the shaft (1), which runs from the drive through the toothed belt wheel through the pump housing before it becomes the distributor piston, is divided in such a way that the rotation is transmitted to it, but a certain stroke is made possible for it. This stroke is achieved by a revolving disc (3) provided with front cams, which runs on a more or less fixed roller ring (2).

For example, the distributor piston in the four-cylinder Golf Diesel is raised four times by the four rollers of the roller ring in one rotation, which means that it can supply the injection nozzles of the four cylinders with high pressure according to the injection sequence 1 3 4 2, 130 bar is sufficient to open them and then increasing further. The injection instant of time can, however, be adjusted by slightly turning the roller ring so that it can take place earlier at higher engine speeds.

Here again the distributor injection pump with toothed belt drive wheel (camshaft speed), tank and fuel filter and the rotated vane pump that sucks the fuel out of the tank and pushes it into the interior. It is filled with fuel as completely as possible, is constantly vented and its pressure increases with the delivery rate of the vane pump, i.e. with the engine speed. It acts on a spring-loaded piston, also shown rotated below, which rotates the roller ring accordingly against the direction of travel of the cam plate.

The inlet to the high pressure chamber can be closed by an electromagnetic valve (7) so that the engine can be switched off. The end of delivery, which at the same time regulates the very important allocation of the injection quantities, is complicated. For this purpose, the pressure chamber of the distributor piston is connected through the middle with a transverse bore that is closed by a ring. If the bore is released, the pressure collapses, which means the end of delivery.

This ring is now not directly connected to the accelerator pedal, but its position is influenced by a centrifugal governor (6) and a complicated set of springs in the transmission lever. This achieves a stable idling and an urgently required reduction in full load. This has priority over any position of the accelerator pedal.