Fuel Pump: Description and Operation

Pump And Sending Unit Mounting:

The electric fuel pump located in the fuel tank consists of an armature, magnet, impeller, brush, check valve, relief valve, etc. The control relay and the ECM control its "ON/OFF" operation.

Fuel Pump:

When power is supplied to the fuel pump, the motor in the pump runs and so does the impeller. This causes a pressure difference to occur between both sides of the impeller as there are many grooves around it. Then the fuel is drawn through the inlet port, and with its pressure increased it is discharged through the outlet to the fuel feed line. Located in the fuel pump is a check valve to hold fuel pressure within the fuel feed line when the vehicle is not in operation.