Patent ID: 8326517

Claim:
A control device for a spark-ignition internal combustion engine equipped with a cylinder pressure sensor, comprising: means for setting a target value of a predetermined combustion-related parameter correlated with a combustion state; means for setting ignition timing based on a control value and an operating condition of the internal combustion engine including at least engine speed, the target value of the combustion-related parameter being used as the control value; means for operating an ignition device of the internal combustion engine in accordance with the ignition timing thus set; means for calculating a value of the combustion-related parameter from an output value of the cylinder pressure sensor; feedback means for calculating a correction amount of the control value based on a deviation between the calculated value and the target value of the combustion-related parameter; means for calculating a value of a predetermined combustion variation parameter correlated with the magnitude of a combustion variation from the output value of the cylinder pressure sensor; and means for stopping the feedback means correcting the control value if the calculated value of the combustion variation parameter exceeds a predetermined threshold value.