Liquid fuel injection pumps

A liquid fuel injection pumping apparatus for supplying fuel to an internal combustion engine and comprising a housing, a rotary distributor member located in the housing, an injection pump including a bore formed in the distributor member, a pump plunger located in said bore, and cam means for imparting inward movement to said plunger as the distributor member rotates, a delivery passage in the distributor member through which the fuel displaced from said bore during the inward movement of the plunger flows, a plurality of outlet ports in the housing said delivery passage communicating with said outlet ports in turn as the distributor member rotates so that the fuel displaced during successive inward movements of the plunger will flow to the outlet ports in turn, a further bore formed in the distributor member or in a port rotatable therewith, a further plunger in said further bore, conduit means connecting said bores, further cam means for imparting inward movement to said further plunger as the distributor member rotates, said further cam means being positioned so that fuel will be displaced from said further bore through said conduit means to said first mentioned bore whilst the delivery passage is out of register with the outlet ports, valve means in said conduit means operable to allow fuel to flow to said first mentioned bore but to prevent the reverse flow of fuel, said valve means acting to ensure restriction to the flow of fuel to the first mentioned bore, and means operable in conjunction with said further cam means to determine the length of the stroke of said further plunger during which fuel can be delivered to said first mentioned bore.