Fuel System Applications

(1) Returnable fuel systems return fuel to the fuel tank by means of a return line from the fuel rail.

(2) Mechanical returnless fuel systems do not return fuel to the fuel tank by means of a fuel return liner The pressure regulator is mounted on the Fuel Pump Module located in the fuel tank and excess fuel is returned at this point.

(3) Electronic fuel systems do not return fuel to the fuel tank by means of a fuel return line. There is no fuel pressure regulator and pressure is controlled by varying the voltage to the fuel pump through the Fuel Pump Driver Module (FPDM).

(4) Fuel returned to fuel tank from fuel rail and pump speed is variably controlled by the FPDM.