Figure 154. Fixing the fuel injection pump regulator: 1 — Fuel injection pump; 2 - lock bolt; 3 - regulator with a protrusion
The first method uses a pump, which helps determine the exact injection moment based on pressure. For the second, a control device is used, which is screwed into the hole in the regulator body, shown in the figure 154. Using a device with two control lamps, the start of injection is accurately determined by marks on the crankshaft pulley.
Mercedes branded service stations use a special tester with a digital sensor.
Figure 155. Injection timing adjustment screw
It should also be noted that the injection start timing can be adjusted while the engine is running. For this purpose, the fuel injection pump flange is equipped with an adjusting screw, shown in the figure 155. When the screw is tightened, a later injection moment is set; when it is loosened, an earlier one is set.