Abstract: A fuel injection system for supplying pressurized fuel to a fuel injector, the fuel injection system comprising an accumulator volume for supplying fuel at a first injectable pressure level to the fuel injector through a fuel supply passage, a pump arrangement for increasing the pressure of fuel supplied to the injector to a second injectable pressure level, and a valve arrangement operable between a first position in which fuel at the first injectable pressure level is supplied to the injector and a second position in which communication between the injector and the accumulator volume is broken so as to permit fuel at the second injectable pressure to be supplied to the injector. The injection system may include a valve arrangement in the form of a three-position valve or may include a shut off valve for controlling the supply of fuel through the fuel supply passage.

Abstract: A fuel system for use in an internal combustion engine comprising a fuel pump having a pumping cycle during which fuel is pressurised to a high level within a pumping chamber for delivery to an injector. The injector is arranged to provide a primary fuel injection event, and a secondary fuel injection event within the same pumping cycle. The injector includes a valve needle which is engageable with a valve needle seating to control fuel delivery and an injection control valve arrangement for controlling movement of the valve needle so as to control the primary and secondary fuel injection events. The fuel system further comprises an accumulator volume for storing high pressure fuel for delivering the secondary fuel injection quantity, and additional valve arrangement for controlling the supply of fuel stored within the accumulator volume to the injector for the secondary injection event.

Abstract: A fuel injection system for supplying pressurised fuel to a fuel injector, the fuel injection system comprising an accumulator volume for supplying fuel at a first injectable pressure level to the fuel injector through a fuel supply passage, a pump arrangement for increasing the pressure of fuel supplied to the injector to a second injectable pressure level, and a valve arrangement operable between a first position in which fuel at the first injectable pressure level is supplied to the injector and a second position in which communication between the injector and the accumulator volume is broken so as to permit fuel at the second injectable pressure to be supplied to the injector. The injection system may include a valve arrangement in the form of a three-position valve or may include a shut off valve for controlling the supply of fuel through the fuel supply passage.

Abstract: A fuel system for use in an internal combustion engine comprising a fuel pump having a pumping cycle during which fuel is pressurised to a high level within a pumping chamber for delivery to an injector. The injector is arranged to provide a primary fuel injection event, and a secondary fuel injection event within the same pumping cycle, in use. The injector includes a valve needle which is engageable with a valve needle seating to control fuel delivery and an injection control valve arrangement for controlling movement of the valve needle so as to control the primary and secondary fuel injection events. The fuel system further comprises an accumulator volume for storing high pressure fuel for delivering the secondary fuel injection quantity, and additional valve arrangement for controlling the supply of fuel stored within the accumulator volume to the injector for the secondary injection event.