Fuel pump module. Fuel pump

Fuel pump module

DESCRIPTION

The fuel pump module on all models/all engines is installed in the top of the fuel tank (Fig. 1). The fuel pump module contains the following components (Fig. 2):

• A combination fuel filter/fuel pressure regulator
• Electric fuel pump
• Fuel pump reservoir
• A separate in-tank fuel filter (at bottom of module)
• Fuel gauge sending unit (fuel level sensor)
• Fuel supply line connection at filter/regulator
• A metal lockring to retain pump module to fuel tank
• A gasket between tank flange and module

The fuel gauge sending unit (fuel level sensor), and pick-up filter (at bottom of module) may be serviced separately. If the electrical fuel pump requires service, the entire fuel pump module must be replaced.

Fig. 1 Fuel Pump Module/Fuel Tank (Top View)

1 - FUEL PUMP MODULE

2 - FRONT ROLLOVER VALVE

3 - FUEL FILTER/FUEL PRESSURE REGULATOR

4 - FUEL TANK

5 - EVAP LINE

6 - REAR ROLLOVER VALVE

OPERATION

Refer to Fuel Pump, Fuel Filter/Fuel Pressure Regulator and Fuel Gauge Sending Unit.

Fuel pump

DESCRIPTION

The fuel pump is located inside of the fuel pump module. A 12 volt, permanent magnet, electric motor powers the fuel pump.

OPERATION

Voltage to operate the electric pump is supplied through the fuel pump relay.

Fuel is drawn in through a filter at the bottom of the module and pushed through the electric motor gearset to the pump outlet.

Check Valve Operation: The pump outlet contains a one-way check valve to prevent fuel flow back into the tank and to maintain fuel supply line pressure (engine warm) when pump is not operational. It is also used to keep the fuel supply line full of gasoline when pump is not operational. After the vehicle has cooled down, fuel pressure may drop to 0 psi (cold fluid contracts), but liquid gasoline will remain in fuel supply line between the check valve and fuel injectors. Fuel pressure that has dropped to 0 psi on a cooled down vehicle (engine off) is a normal condition. Refer to the Fuel Pressure Leak Down Test for more information.

Fig. 2 Fuel Pump Module Components (Typical Pump Module Shown)

1 - FUEL FILTER/PRESSURE REGULATOR

2 - ELECTRICAL CONNECTOR

3 - ELECTRIC FUEL PUMP

4 - FUEL GAUGE FLOAT

5 - FUEL PUMP INLET FILTER

6 - FUEL GAUGE SENDING UNIT

7 - MODULE LOCK TABS (3)