Abstract: A fuel injection pump for supplying fuel to an internal combustion engine includes a plunger reciprocable within a bore by cams on a cam ring. Fuel is supplied to the bore by a throttle. A first valve is provided which connects a point intermediate the throttle and the bore with a drain. A second valve is provided to ensure that the pressure applied to the outer end of the plunger is above said drain pressure. When the first valve is opened the pressure acting at the outer end of the plunger will move it inwardly to ensure that it cannot be actuated by the cam.

Abstract: A fuel system for an internal combustion engine includes a pump/injector having an actuating winding to which power is supplied by a first electronic means. A first control signal is supplied by a second electronic means to energize the winding and a second control signal is supplied by a third electronic means to de-energize the winding. The third electronic means calculates the time at which the winding should be de-energized to allow the piston in the pump to draw in the required volume of fuel, the second electronic means causing delivery of fuel when the required volume of fuel has been drawn into the pumping chamber of the pump.

Abstract: A fuel system for supplying fuel to an engine includes a nozzle positioned to direct fuel into a combustion chamber and an electromagnetically operable pump for supplying fuel to the nozzle. A first electronic means supplies power to a winding of the pump to cause delivery of fuel and holds the pumping piston of the pump until it is required to fill the pumping chamber of the pump. A second electronic means partly energizes the winding or another winding when the required amount of fuel has flowed into the pumping chamber, to hold the piston against movement.