Bosch Fuel Supply Pump Intermediate Stroke Position
As the injection pump camshaft continues to revolve, it forces the roller tappet of the supply pump outward, away from the injection pump, also pushing the plunger out. Fuel trapped in the suction chamber will open the pressure valve and enter the pressure chamber. This fuel will also close the suction valve on the inlet line. This stroke completely fills the pressure chamber so that it can empty on the discharge stroke.