Fuel pump injector

A fuel pump injector for mounting on an internal combustion engine so as to deliver fuel to a combustion space of the engine, the injector comprising in combination a housing, a bore defined in the housing, a plunger slidable within the bore, an outlet at one end of the bore, a valve for controlling fuel flow through said outlet, a fuel supply port opening into the bore at a position so that it is covered by the plunger during movement thereof towards said one end of the bore and an electromagnetic device for urging the plunger towards said one end of the bore whereby when said port is covered fuel is discharged through said outlet, said injector including a return spring for said plunger, said outlet comprised of an insert which is retained in said bore at said one end thereof, said insert defining a valve seat, said valve cooperating with said seat, said valve comprising an extension which is mounted on a cylindrical port slidable within a bore formed in said plunger, said bore being a blind bore and housing a spring action to urge said extension into contact with said seat, wherein said blind bore communicates with a further port formed in the wall of the bore mounting the plunger, said port and further port communicating with a fuel supply passage in the housing.