The injection start of the high-pressure fuel pump must be checked and adjusted after tensioning, removing or replacing the toothed belt, as well as loosening the fuel pump mounting bolts or belt toothed wheels.
Examination
1. Set the crankshaft to the TDC position of the piston of the first cylinder, refer to the subsection Setting the piston of the first cylinder to TDC.
2. Fix the camshaft with an adjusting ruler, refer to the subsection Setting the piston of the first cylinder to TDC.
3. Now the VW–3359 rod should enter the hole in the hub of the gear wheel and the fuel injection pump holder. This way, the position of the fuel injection pump is fixed. The rod should enter so that the hole (arrow on the accompanying illustration) stood at a distance of approximately 3 mm in front of the pump hub.
Warning: Instead of the VW–3359 rod, you can use any rod ∅ 6 mm, for example, a drill.
4. If the rod does not enter the injection pump hole, despite the fact that the TDC marking and the position of the camshaft match, it is necessary to check the fuel injection start adjustment again.
Adjusting the injection start
5. Loosen the fastening bolts –1– of the injection pump toothed wheel so that the toothed belt wheel can turn relative to the pump hub.
Warning: The central mounting bolt on the pump hub should not be loosened, otherwise the pump will shift and it will not be possible to adjust it at home.
6. Turn the fuel injection pump hub so that the rod enters.
Note: The rod must be inserted so that the hole (arrow on the illustration) stood at a distance of approximately 3 mm in front of the pump hub.
7. The rod should enter so that the hole (arrow on the illustration) stood at a distance of approximately 3 mm in front of the pump hub.
8. Remove the rod.
9. Remove the adjustment ruler.
10. Turn the crankshaft 2 revolutions in the direction of engine rotation and set it again to the TDC position of the piston of the first cylinder. Check the position of the markings on the flywheel and camshaft.
11. Fix the fuel injection pump gear with a rod. If the rod does not enter the fuel injection pump hole, repeat the adjustment process.
12. Remove the rod.
13. Install the cylinder head cover gasket. Secure the cover, tightening torque 10 Nm.
14. Install the upper timing belt cover.
15. Insert a plastic plug into the hole in the clutch housing.
Warning: Finally, check the dynamics of the injection start of the high-pressure fuel pump (work of the service station).
Warning: After fine-tuning the injection start timing, tighten the 3 fuel injection pump gear mounting bolts to 20 Nm and then turn them 90° further (1/4 turn). If the bolts have been tightened in the manner specified, they must be replaced with new ones after being unscrewed.