Abstract: A fuel system comprises a fuel pump arranged to deliver fuel to a single fuel injector. The fuel pump and injector are physically spaced apart from one another, a high pressure fuel line being used to convey fuel between the fuel pump and the injector. The fuel pump is controllable to control the timing of commencement of fuel pressurization. The injector is controllable to control the timing of fuel delivery. A controller is arranged to control the operation of the fuel pump and the injector. The invention further relates to a fuel pump suitable for use in such a fuel system.

Abstract: A pump injector comprising a pumping chamber, a valve needle controlling communication between the pumping chamber and one or more outlet openings, and a spill valve controlling communication between the pumping chamber and a low pressure fuel reservoir, in use. The pump injector also comprises an inlet non-return valve arranged to permit fuel to flow from the fuel reservoir to the pumping chamber, in use, but substantially preventing fuel flow in the reverse direction. Alternatively, the pump injector may comprise an abutment piston engageable with the valve needle which defines, in part, a control chamber for fuel, and a control valve controlling communication between the pumping chamber and the control chamber.

Abstract: An injector is disclosed which comprises a nozzle body arranged to receive fuel under pressure from a pumping chamber. An injection control arrangement in the form of a valve controls injection timing, and a drain control arrangement in the form of a valve controls communication between the pumping chamber and a fuel reservoir. An electromagnetic actuator controls operation of both valves, the actuator including a single, common armature which is associated with both of the valves.