Ignition timing control method for internal combustion engines

摘要

An ignition timing control method for an internal combustion engine in which an ignition advance angle value conforming to the operating condition of the engine is set, an ignition timing is obtained by applying an angle-time conversion to a crank angle extending from a reference crank angle position to a position corresponding to the ignition advance angle value, and ignition is effected upon lapse of the ignition timing from an instant at which the reference crank angle position is sensed. Engine rotational speed value is sensed at least at two particular crank angle positions, and each sensed rotational speed is stored in memory. A ratio between the at least two rotational speed values stored in an immediately preceding ignition cycle is calculated, and the ignition timing of a present ignition cycle is corrected by using the calculated ratio.