Fuel injection system for internal combustion engine

The device has a high pressure pump (18) feeding fuel under high pressure to a storage device (32) connected to injectors (40), a delivery pump (10) feeding fuel to the high pressure pump from a tank (12). The high pressure pump working chamber (34) is connected to the pressure side of the delivery pump and contains a suction valve (36) opening to the working chamber and with a minimal opening pressure difference less than 0.9 bar.