Fuel Pump Description

FUEL PUMP

Fuel Pump:

The fuel pump motor, located inside the fuel tank as an assembly to the primary fuel pump module (right side of fuel tank), supplies fuel pressure to the fuel injectors. The ECM controls the fuel pump motor by controlling the fuel pump relay in the Underhood Fuse Block (UHFB). The fuel pump motor is supplied constant ignition voltage whenever the fuel pump relay is turned On. The ECM turns On the fuel pump relay whenever the engine is running or cranking. The ECM will NOT run the fuel pump unless crankshaft position sensor pulses are being received.

The fuel pump is a single stage, turbine style, 12 volt unit controlled by the Powertrain Control Module (PCM). The PCM supplies a 12 volt feed to a relay in the Left Instrument Panel Fuse Block (LIPFB). This relay controls a 12 volt supply to the fuel pump.

The fuel pump will only operate with ignition On and engine running or cranking. With ignition On, pump relay is only energized for 2-3 seconds and will be disabled if PCM does not see reference pulses from the electronic ignition module. To re-initialize pump, ignition must be turned Off for at least 10 seconds

The pump is capable of delivering over 2 liters (0.528 gallons) of fuel per minute but is required to supply less than 1 liter (0.264 gallons) per minute to meet engine demands.

The pump incorporates two check valves to control system pressures. The outlet check valve maintains fuel system pressure after the ignition is turned off to insure quick starts. A pressure relief valve protects the fuel system from damage as a result of excessive pressure.

Fuel is filtered before entering the pump by:
^ A single-stage mesh filter for the return fuel located within the housing. This filter is not serviced. Problems with this filter (low pressure and/or low fuel flow) indicate a contaminated fuel tank; the tank should be thoroughly cleaned and the pump replaced.