After adjusting the tension of the toothed drive belt or after replacing it, it is necessary to check the adjustment of the high-pressure fuel pump and, if necessary, adjust it. For this purpose, the toothed drive belt pulley (1) of the high-pressure fuel pump has corresponding sections. After the bolts (2) have been unscrewed, the pump hub can be turned accordingly in the longitudinal grooves of the toothed belt pulley. A description of the adjustment work is given below.
To perform this, you need the TDC locking pin (Mot. 1054) and a pointer indicator with adapter (Mot. 856) for the pump stroke. We must warn you that setting the start of the pumping cycle, described below, is a job for a highly qualified professional, which can only be done with the specified special tools! The quality of its execution must be checked in a car repair shop.
1. Set the engine to TDC position for cylinder 1.
2. Adapter instead of threaded plug.
3. Insert the TDC locking pin (Mot. 1054). To do this, first unscrew the plug next to the oil level dipstick.
4. Carefully rotate the motor shaft against the dowel pin.
5. Unscrew the threaded plug from the high pressure fuel pump head in the middle of the high pressure fuel lines.
6. Install the adapter instead of the plug and attach the pointer indicator to it.
7. Tap the pump body lightly to return the centrifugal governor to its original position.
8. Loosen the 3 bolts in the longitudinal grooves of the section pulley of the toothed drive belt and turn the pump hub so that the specified pump stroke is achieved.
9. Tighten the bolts in the longitudinal grooves.
10. Turn the engine shaft in the direction of travel by 2 full turns by hand and check the measurement result again.
11. If necessary, readjust and repeat the procedure by turning the engine.
12. Tighten the bolts into the longitudinal grooves to a torque of 20 Nm.
13. Remove the dial indicator and adapter and tighten the threaded plug with a new sealing ring to a torque of 15 Nm. If there is a leak, tighten to a torque of 25 Nm.