Fuel Pump: Description and Operation

Fuel Pump R And R:

The electric fuel pump, installed in the fuel tank, is submerged in fuel, this suppresses pump operational noise and improves vapor lock resistance. This pump is called "wet type" because the inside is filled with fuel. Two valves are incorporated in the pump assembly, a relief valve (to protect against over pressure), and a check valve (to retain pressure in the system).

High Pressure Elecric Fuel Pump:

Fuel pump operation is controlled by the Electronic Control Unit (ECU), through the engine control relay. Power is supplied to the fuel pump by the engine control relay through separate circuits for cranking and run modes. In the event of engine stall or other abnormal conditions, the ECU interrupts the fuel pump power circuit.
NOTE: Failure of the engine control relay may interrupt power supply to the fuel pump, injectors and/or the ECU, resulting in failure to start.