Ignition timing control system for an automotive engine

Claim 1

An ignition timing control system for an automotive engine, comprising: means for detecting driving conditions of a motor vehicle driven by the engine and for producing a driving condition signal; first circuit means responsive to the driving condition signal for deciding ignition timing; detecting means for detecting the magnitude of the acceleration of the engine and for producing an acceleration signal; knock detecting means for detecting knock of the engine and for producing a knock signal the level of which is dependent on the magnitude of the knock; second circuit means responsive to the knock signal for producing an advance/retard signal; correcting circuit means for correcting the advance/retard signal; a plurality of first areas in a memory for storing advance/retard correcting values; first selecting circuit means for designating one of the first areas in the memory in accordance with the driving condition signal and the acceleration signal and for storing an advance/retard signal corrected by the correcting circuit means; second selecting means for deriving the corrected advance/retard signal from a designated area in the first areas and for sending it to the correcting circuit means so as to correct the advance/retard signal.