Abstract: A fuel injection system for internal combustion engines includes an improved direct injection pump having a reciprocating metering plunger and an improved injector for atomizing and injecting the fuel into the combustion chamber. Respective moving parts of the pump and injector are supported in low friction seals free of contact with other parts and require no lubrication from the fuel pumped or from other sources so as to operate efficiently without galling on gasoline or diesel engines on any combustible fuel or any combination of such fuels. The pump includes a housing provided at one end with a fuel chamber of a predetermined capacity that has a single opening for receiving fuel from a source of supply through a valved fuel inlet and from which opening, fuel is dispensed to the injector through a valved fuel outlet line.