Patent ID: 7770566

Claim:
A method for controlling an internal combustion engine intended to operate either with gasoline or with alcohol or with a variable proportion of the gasoline or alcohol, including an electronic control unit capable of controlling the engine, an intake manifold, and an exhaust pipe including a richness sensor, the method comprising: injecting a fuel mixture present in a tank of the engine at a predetermined injection period; determining richness of a hydrocarbon and air mixture entering combustion cylinders; increasing, according to the richness of the hydrocarbon and air mixture, the injection period in stages to adjust the injection period of the fuel mixture present in the tank of the engine and to obtain a generally stoichiometric hydrocarbon and air mixture; and storing a fraction of the adjusted injection period that obtains the generally stoichiometric hydrocarbon and air mixture as the predetermined injection period to be used during the injecting a next time the engine is started.