After adjusting the tension of the toothed drive belt or after replacing it, the adjustment of the high pressure fuel pump must be checked and, if necessary, corrected. To do this, the toothed belt pulley (1) the high pressure fuel pump has corresponding sections. After the bolts are loosened (2), 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 do this, a TDC locking pin is required (Mot. 1054), as well as a pointer indicator with an adapter (Mot. 856) to run the pump. You should be warned that setting the start of the injection cycle described below is a job for a highly trained professional that can only be done with the specified special tools! The quality of its implementation should be checked in a car repair shop.
1. Set the engine to the TDC position for the 1st cylinder.
2. Adapter instead of screw plug.
3. Insert TDC locking pin (Mot. 1054). To do this, first unscrew the plug next to the dipstick to measure the oil level.
4. Gently rotate the motor shaft against the dowel pin.
5. Remove the screw 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 fix the dial indicator on it.
7. Tap lightly on the pump housing to return the centrifugal regulator to its original position.
8. Loosen the 3 bolts in the longitudinal grooves of the sectional pulley of the toothed drive belt and turn the pump hub so that the pump stroke prescribed for the pump is reached.
9. Tighten the bolts in the slots.
10. Rotate the motor shaft in the direction of travel 2 full turns by hand and check the measurement again.
11. If necessary, adjust again and repeat the procedure with the engine cranking.
12. Tighten the bolts in the longitudinal grooves with a torque of 20 Nm.
13. Remove the dial indicator and adapter and tighten the screw plug with a new sealing ring to a torque of 15 Nm. In case of leaks, tighten to 25 Nm.