Fuel System

The fuel system consists of:

• the electric fuel pump which provides pressurized fuel to the engine.
• the fuel level sensor.
• the fuel pump inlet filter (filter sock).
• a check valve which maintains system pressure after the pump is shut off.
• a parallel pressure relief valve (with bleed port) which maintains fuel in the system after the fuel pump is shut off.
• a fuel pump driver module (FPDM) that controls the fuel pump based on input received from the powertrain control module (PCM).

The fuel pump is controlled by the PCM. Electrical power is provided through the inertia fuel shutoff (IFS) switch. The engines are equipped with sequential multiport fuel injection (MFI). The PCM is able to maintain constant fuel pressure by varying fuel pump module (FPM) output. This is accomplished by increasing or decreasing voltage supplied to the tank-mounted FPM.