Fuel Pump: Description and Operation

The fuel system consists of:
^ the fuel tank.
- The midship fuel tank is mounted to the LH frame side rail.
- The aft of axle fuel tank is mounted between the side rails.
^ a fuel tank filler pipe without a restrictor plate.
^ a threaded fuel tank filler cap.
^ a fuel filter and water separator to protect the fuel injectors.
^ a fuel circulation/filter unit (located inside the fuel tank on the fuel sender assembly)
^ fuel lines
^ an internal check valve with a built in orifice that will allow system pressure to bleed off after approximately 10 minutes after the pump is shut off.
^ fuel pump is an in-line electric pump mounted on the left hand frame rail, which provides pressurized fuel to the engine and contains:
- an integral non-serviceable coarse inlet filter.
- a pressure relief valve for overpressure protection in the event of restricted flow.
The fuel pump draws fuel from the fuel tank and supplies it to the engine at 310-448 kPa (45-65 psi).

The fuel pump is controlled by the fuel pump Powertrain Control Module relay. Electrical power to the fuel pump is provided through the inertia fuel shutoff switch (IFS switch).

The fuel recirculation/filter unit assist in preventing the fuel from getting in the fuel lines during cold weather operations.