Abstract: In a method for controlling a fuel-supply system, a first supply unit supplies fuel from a storage container to a second supply unit. At least a partial quantity of the fuel quantity supplied by the first supply unit returns to the storage container as return quantity via a return line. The return quantity is determined as a function of the operating state of the fuel-supply system. The first supply unit is controlled at least as a function of the return quantity.

Abstract: The fuel injection device for an internal combustion engine comprises a feed pump which has an electric drive, by which feed pump fuel is fed from a fuel storage tank into a low-pressure region to the suction side of at least one high-pressure pump. The high-pressure pump pumps fuel into a high-pressure region in which at least one injector is provided to inject the fuel into the internal combustion engine. The fuel injection is controlled by an electric control device. Arranged in the low-pressure region is a pressure sensor which is connected to the control device. The electric drive of the feed pump is activated by the control device in order to set a feed quantity of the feed pump which is variable as a function of at least one operating parameter of the internal combustion engine and/or of the high-pressure pump.

Abstract: The invention relates to a high pressure injection system having a fuel tank, a connection line between the fuel tank and a high pressure pump for sealing the fuel, wherein the high pressure pump is connected to at least one fuel injection valve via a corresponding connection line. According to the invention, at least a partial volume of the fuel sealed in the high pressure pump is fed back to the fuel tank from said fuel injection valve by leakage in the fuel injection valve via a return line connected to the fuel tank. An essential characteristic of the invention is that the high pressure injection system comprises a cooling line that connects the fuel tank or the low pressure region to the high pressure or a return of the high pressure pump via a mixing point with the return line. It is thereby possible to cool the fuel in the return lines between the fuel injection valve and the fuel tank.

Abstract: In a method for controlling a fuel-supply system, a first supply unit supplies fuel from a storage container to a second supply unit. At least a partial quantity of the fuel quantity supplied by the first supply unit returns to the storage container as return quantity via a return line. The return quantity is determined as a function of the operating state of the fuel-supply system. The first supply unit is controlled at least as a function of the return quantity.

Abstract: The fuel injection device for an internal combustion engine comprises a feed pump which has an electric drive, by which feed pump fuel is fed from a fuel storage tank into a low-pressure region to the suction side of at least one high-pressure pump. The high-pressure pump pumps fuel into a high-pressure region in which at least one injector is provided to inject the fuel into the internal combustion engine. The fuel injection is controlled by an electric control device. Arranged in the low-pressure region is a pressure sensor which is connected to the control device. The electric drive of the feed pump is activated by the control device in order to set a feed quantity of the feed pump which is variable as a function of at least one operating parameter of the internal combustion engine and/or of the high-pressure pump.