The electric fuel lift pump mounts on the inside of the left frame rail, and is used to deliver fuel at a low pressure (at least 3 psi or 21 kPa) at the rate of 0.24 liter (½ pint) in 15 seconds (15 GPH). The lift pump is controlled by the PCM.

When the key is in turned ON, the PCM energizes the fuel pump relay which sends voltage to the lift pump. The lift pump remains during the glow plug cycle. If the engine is not started immediately after the glow plug cycle, the PCM shuts the fuel lift pump OFF and waits until engine RPM is greater than zero and then turns the relay back ON. As a backup system to the fuel pump relay, the fuel lift pump can also be turned ON by the fuel pump/oil pressure switch. When the engine oil pressure reaches 28 kPa (4 psi), and the fuel pump relay does not complete the circuit, the fuel pump/oil pressure switch will close and complete the circuit to run the fuel lift pump.

The fuel manager/filter is an in-line type filter which combines several different functions. It acts as a fuel filter, water separator, water detector, water drain, and a fuel heater.

The fuel manager/filter mounts on the rear of the intake manifold. The filter housing has an inlet fitting connecting to the pipe/hose from the lift pump and an outlet fitting connecting to the fuel injection pump with a hose. A third fitting connects through a hose to a drain valve mounted on the water crossover/thermostat housing.

The fuel manager/filter has a replaceable element. The element has an air vent valve on its top surface that is used during lift pump diagnosis and filter element replacement procedure. The fuel manager/filter also has a water in fuel sensor and a fuel heater.

The fuel filter element separates particles larger than 10 microns (0.00039 in) from fuel moving through it under lift pump pressure. Filter action is very critical to the operation of internal parts of the fuel injection pump.

The design of the fuel manager/filter includes an area that allows water droplets (as small as one micron) to separate from the fuel and collect in a lower portion of the housing. The water in fuel sensor will detect a certain amount of water in the fuel inside the filter housing and then turn the Water in Fuel lamp ON in the instrument cluster.

When the ignition switch is first turned to the run position, the Water in Fuel lamp will come ON for 2 to 5 seconds. This action provides a bulb check.

The fuel heater operates when the temperature of fuel at the inlet of the filter housing is cold enough to possibly cause waxing that could restrict flow to the injection pump. A control circuit inside the fuel heater completes the circuit for the heater element when it senses a temperature below 8°C (46°F).

The fuel feed and return pipes and hoses extend from the fuel sender to the fuel manager/filter. They are secured with clamps and are routed along the frame side member.

Some fuel feed pipes have threaded connections that are sealed with replaceable O-ring seals. These O-ring seals are made of special material, and should only be serviced with the correct service part.