JPS6456969A - Ignition timing control method for internal combustion engine - Google Patents

Abstract

PURPOSE:To suppress decrease in an engine output to a minimum limit by increasing a delay timing correction amount in accordance with increase of engine speed, in the case of an engine in which the basic ignition timing is obtained from the speed of the engine and its load condition performing the delay timing correction when a cooling water temperature is in a predetermined value or more. CONSTITUTION:During operation of an internal combustion engine 20, referring to a map value stored in a ROM50d being based on outputs from a crank angle sensor 58 and a pressure sensor 36 by a CPU50c in a control unit 46, basic ignition timing is calculated, next it is decided whether or not a water temperature detection value by a water temperature sensor 42 exceeds a predetermined value with possibility of causing knocking, and when the water temperature exceeds the predetermined value, it is decided whether or not the engine speed is in a predetermined value or more. In accordance with the decision result, referring a delay timing correction amount in accordance with the water temperature in that time to a predetermined table determining the delay timing correction amount for use of high speed region or low speed region, the basic ignition timing is corrected being delayed in accordance with this delay timing correction amount.