System and method for controlling ignition timing for internal

Abstract

A system and method for controlling an ignition timing for a vehicular internal combustion, are disclosed in which a basic ignition timing is determined on the basis of engine operating conditions, i.e., an engine revolution speed and pulsewidth of a fuel injection signal supplied to an injection valve for each engine cylinder. A first correction quantity to correct the basic ignition timing is determined on the basis of a change rate of the engine revolution speed. A second correction quantity to correct the basic ignition timing is determined on the basis of an engine load. A final ignition timing is determined on the basis of the basic ignition timing and/or first and second correction quantities when the engine falls into a transient operating condition, any one of shift gear positions is detected, the gear shift positions including a position in which no engine driving force is transmitted to a vehicular power train. The final ignition timing is determined according to the gear shift range position. In addition, when the gear shift is placed in the position in which no engine driving force is transmitted to the power train and the change in the engine revolution speed occurs, the basic ignition timing is determined to be the final ignition timing.