Fuel Distributor
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1987 Volkswagen Scirocco, 1987 Volkswagen Quantum, 1987 Volkswagen Jetta, 1987 Volkswagen Golf, and 1987 Volkswagen GTI. However, it is still accessible from the selected car via links, so may be relevant.
The fuel distributor controls the flow of fuel to the injectors. A control plunger, operated by the airflow sensor regulates the control pressure differential between the injector supply (upper chamber) and the lower chamber (fuel return). This differential in pressure controls the amount of fuel flow to the injectors. The electrically controlled, differential pressure regulator also controls fuel flow from the lower chamber.