IGNITION TIMING CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES

摘要

An ignition timing control system controls igintion timing of spark plugs of an internal combustion engine associated with a plurality of changeover devices, changeover of an operative state of each of which has influence upon output torque of the engine. Operating conditions of the engine are detected. A basic ignition timing advance value is calculated based on results of detection of the operating conditions of the engine. A changeover of the operative state of each of the changeover devices is detected. A correction value for correcting the basic ignition timing advance value for suppressing the engine torque is calculated, in response to results of detection of the changeover of the operative state of each of the changeover devices. The largest one of a plurality of the correction values calculated is selected to a final correction value to be used for correcting the basic ignition timing advance value, when changeovers of the operative states of at least two of the changeover devices are detected substantially at the same time.