Patent ID: 7219654

Claim:
A fuel injection system for an internal combustion engine, the system comprising a high-pressure pump that delivers fuel at high pressure to an accumulator, a fuel supply pump that delivers fuel to the suction side of the high-pressure pump, a fuel metering unit connected between the fuel supply pump and the high-pressure pump and operable to variably adjust the fuel quantity taken in by the high-pressure pump, at least one injector connected to the accumulator for injecting fuel into the engine, a fuel return from the at least one injector, the fuel return from the at least one injector feeding into the connection between the fuel supply pump and the fuel metering unit, and a connection controlled by a pressure valve leading from the fuel return to a discharge region, the high-pressure pump only drawing fuel from the fuel return in operating states in which the fuel quantity delivered by the fuel supply pump is less than the required intake quantity of the high-pressure pump.