Method for controlling ignition timing of internal combustion engine and

Abstract

A method for controlling ignition timing of an internal combustion engine and an apparatus for practicing the method are disclosed which are adapted to determine ignition timing depending upon information on an engine speed detected, to thereby control the ignition timing. Pulsin signal counting is started evey time when a reference signal is generated from a signal generator to count first, second and third numbers N1, N2 and N3 of pulse signals, to thereby obtain information on an engine speed depending upon the difference between time T2 when the counting of the second number of pulse signals is completed and time T1 when that of the first number of pulse signals is completed, and then the information is used for obtaining ignition timing measuring time equal to a period of time between time T3 when the counting of the third number of pulse signals is completed and target ignition timing T1. The measuring of the ignition timing measuring time is started after the counting of the third number N3 of pulse signals is completed.