Abstract: A fuel injection system for internal combustion engines in which fuel is injected, under pressure, into an insulated fuel injection chamber wherein it mixes with incoming air and vaporizes. Heat absorbed in the evaporation of the fuel is taken primarily from the incoming air and from the incoming fuel in the fuel line, which is wrapped about the fuel injection chamber within the insulation, the resulting fuel-air mixture introduced into the combustion chamber is in both a super-cooled and a highly vaporized state.