Abstract: In one embodiment of the present invention, a "returnless" fuel delivery system for a motor vehicle includes a fuel pressure regulator located in the fuel tank and a fuel pressure damper located at the fuel rail on the vehicle's engine. The fuel return line from the fuel rail to the fuel tank, a conventional feature in fuel delivery systems, is eliminated. Fuel delivery systems according to the present invention can provide very precise fuel delivery at a highly competitive system cost.

Abstract: In one embodiment of the present invention, a "returnless" fuel system for a motor vehicle is disclosed. A "series-pass" fuel pressure regulator in the system provides fuel of a regulated pressure to a fuel rail comprising at least one fuel injector. A "bypass" fuel pressure regulator provides fuel with a regulated pressure to the series pass regulator. An in-line fuel filter is located downstream from the bypass regulator, such that only the fuel which reaches the series-pass regulator is filtered. A check valve is located downstream from the bypass regulator as well, to prevent fuel pressure bleed-down through the fuel pump and the bypass regulator. A pressure relief valve is coupled to allow fuel with a pressure above a predetermined value to flow around the check valve.