Fuel Pump Relay: Description and Operation

To control fuel pump operation, a fuel pump relay is used.

When the ignition switch is turned to "ON" position, the fuel pump relay activates the electric fuel pump for 1.5 to 2.0 seconds to prime the injector. If the Engine Control Module (ECM) does not receive reference pulses from the distributor after this time, the ECM signals the relay to turn off the fuel pump. The relay will once again activate the fuel pump when the ECM receives distributor reference pulses.