Fuel Pump: Description and Operation

Pump And Sending Unit Mounting:

PURPOSE
Provides constant, pressurized fuel to the fuel injection components.

LOCATION
In the fuel tank.

OPERATION
The control relay and the ECM control its "ON/OFF" operation.
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.

Fuel Pump:

CONSTRUCTION
Consists of an armature, magnet, impeller, brush, check valve, relief valve, etc.