Fuel Pump: Description and Operation

Fig. 9 Fuel Pump Module:

FUEL PUMP MODULE
The fuel pump module is installed in the top of the fuel tank Fig. 9. The fuel pump module contains the following:
- Electric fuel pump.
- Fuel pump reservoir
- Inlet strainer.
- Fuel pressure regulator.
- Fuel gauge sending unit
- Fuel supply and return line connections

The inlet strainer, fuel pressure regulator and level sensor are the only serviceable items. If the fuel pump requires service, replace the fuel pump module.

ELECTRIC FUEL PUMP
The electric fuel pump is located in and is part of the fuel pump module. It is a positive displacement, gerotor, immersible pump with a permanent magnet electric motor.

The fuel pump module is suspended in fuel in the fuel tank. The pump draws fuel through a strainer and pushes it through the motor to the outlet.

The pump contains two valves.
- One valve relieves internal fuel pump pressure and regulates maximum pump output.
- The second valve, in the pump outlet, maintains pump pressure during engine off conditions.

The fuel pump relay provides voltage to the fuel pump.

The fuel pump has a maximum deadhead pressure output of approximately 900 kPa (130 psi).

The regulator adjusts fuel system pressure to approximately 338 kPa (48 psi).