Fuel Control System
The fuel control system starts with the fuel in the fuel tank. An electric fuel pump, located in the fuel tank with the gauge sending unit, pumps fuel to the fuel rail through an in-line fuel filter. The pump is designed to provide fuel at a pressure above the pressure needed by the injectors.
A pressure regulator in the fuel rail keeps fuel available to the injectors at a constant pressure. Unused fuel is returned to the fuel tank by a separate line. In order for the fuel injectors to supply a precise amount of fuel at the command of the ECM, the fuel supply system maintains a constant pressure of approximately 35 psi (2.5 kg/cm2 ) drop across the injectors.
As manifold vacuum changes, the fuel system pressure regulator controls the fuel supply pressure to compensate. The fuel pressure accumulator, used on selected applications, isolates fuel line noises. The fuel rail is bolted rigidly to the engine. It provides the upper mount for the injectors. It also contains a spring-loaded pressure tap for testing the fuel system.