Fuel Pump

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 (.528 gallons) of fuel per minute but is required to supply less than 1 liter (.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.

  The fuel level sender is a variable resistor that is read by the engine control module (ECM). The ECM reads resistance and controls the fuel level gauge in response to float movements of sender.

  The level sender is mounted on the module housing and is a snap-lock attachment. The sender and float are serviced as a unit.