Patent ID: 6913004

Claim:
A method for controlling a fuel system and delivering fuel to an internal combustion engine, the fuel system induding at least one fuel injector having at least one capillary flow passage, a heat source arranged along the at least one capillary flow passage, the heat source capable of heating the liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state, the method comprising the steps of: (a) determining engine air flow; (b) measuring a value indicative of degree of engine warm-up; (c) determining a portion of liquid fuel to be converted to the vapor state by the at least one capillary flow passage, said determining step employing the value measured in steps (a)-(b); (d) controlling power supplied to the heat source of the at least one fuel injector to achieve a predetermined target temperature, the predetermined target temperature operable to convert the portion of liquid fuel to the vapor state determined in step (c); and (e) delivering the fuel to a combustion chamber of the internal combustion engine; wherein the portion of liquid fuel to be converted to the vapor state is determined to achieve minimal exhaust emissions, wherein said step of controlling power supplied to the heat source of the at least one fuel injector includes the step of setting a resistance value, the resistance value relatable to the predetermined target temperature and wherein during engine cranking, the power supplied to the heat source of the at least one fuel injector is controlled to a resistance value sufficient to achieve a predetermined target temperature equal to or greater than a final boiling point of the fuel at a pressure about equal to fuel system supply pressure.