Abstract: A dual tank fuel system has primary and secondary fuel tanks, with the primary tank including a filler pipe to receive fuel and a discharge line to deliver fuel to an engine, and with a balance pipe interconnecting the primary tank and the secondary tank. The balance pipe opens close to the bottom of each tank to direct fuel from the primary tank to the secondary tank as the primary tank is filled, and to direct fuel from the secondary tank to the primary tank as fuel is discharged from the primary tank through the discharge line. A vent line has branches connected to each tank to direct fuel vapor from the tanks as the tanks are filled, and to admit air to the tanks as fuel is delivered to the engine.

Abstract: The invention relates to a fuel pressure control system for an electromechanical fuel injection system. The fuel injection system includes a fuel rail for receiving pressurized fuel from a fuel source and operable to supply pressurized fuel to a fuel injector. The fuel rail pressure control system includes a pressure regulator having a flexible diaphragm separating a reference pressure chamber and a fuel chamber. The fuel chamber has a fuel inlet and a fuel outlet. The flexible diaphragm operates to open and close the fuel outlet to balance forces between the reference pressure chamber and the fuel chamber. The fuel chamber is in fluid communication with the fuel rail at the fuel inlet and in fluid communication with a fuel return line at the fuel outlet.