Fuel system for an internal combustion engine

A fuel system for an internal combustion engine includes at least four fuel injectors (12) for supplying fuel to corresponding combustion chambers of the engine and a pump assembly (20) in fluid communication with the fuel injectors and supplying working fluid to the fuel injectors. The fuel system further includes at least three high pressure rails (26, 28, 30, 32) fluidly connected between the pump assembly and the at least four fuel injectors.