System and method for controlling a combustion state in a multi-cylinder engine for a vehicle

摘要

A system and method for controlling combustion state for an internal combustion engine during engine idling which measures the angular speed of the engine cylinders for a certain interval whenever a predetermined crank angle is reached, and detects a combustion state of a given cylinder in the combustion stroke when the engine is idling according to change in the angular speed. The system (method) also divides the engine cylinders into a plurality of cylinder groups, each group having a pair of engine cylinders, the angular speeds in each pair of engine cylinders (cylinder group) are compared and the ignition timing and/or fuel injection quantity is corrected so that the angular speed of the pair of cylinders (cylinder group) which is higher than that of the other cylinder groups is reduced and, for the pair of cylinders in which the angular speed is slower, corrects the ignition timing and/or fuel injection quantity in the reverse direction to the corrected ignition timing and/or fuel injection quantity by the same quantity so that balance between the angular speeds of the pairs of cylinders is taken, whereby the ignition timing and fuel injection quantity is corrected so that a total sum of the correction quantities for all cylinders in the case of the ignition timing and/or fuel injection quantity always becomes zero.