Abstract: The alcohol concentration detection value estimated or detected by the alcohol concentration sensor is corrected in accordance with intensity, frequency and the like of knocking to set the alcohol concentration detection value after the correction as the alcohol concentration for ignition timing control. Thereby, occurrence of the knocking can be prevented by changing ignition timing in accordance with the knocking state. In regard to the fuel injection control, the alcohol concentration detection value before the correction is used as the alcohol concentration for fuel injection control as it is without using the alcohol concentration detection value corrected in accordance with the knocking state. This prevents a fluctuation of the fuel injection quantity due to correcting the alcohol concentration detection value in accordance with the knocking state, leading to prevention of a torque fluctuation or combustion deterioration.

Abstract: The alcohol concentration detection value estimated or detected by the alcohol concentration sensor is corrected in accordance with intensity, frequency and the like of knocking to set the alcohol concentration detection value after the correction as the alcohol concentration for ignition timing control. Thereby, occurrence of the knocking can be prevented by changing ignition timing in accordance with the knocking state. In regard to the fuel injection control, the alcohol concentration detection value before the correction is used as the alcohol concentration for fuel injection control as it is without using the alcohol concentration detection value corrected in accordance with the knocking state. This prevents a fluctuation of the fuel injection quantity due to correcting the alcohol concentration detection value in accordance with the knocking state, leading to prevention of a torque fluctuation or combustion deterioration.

Abstract: A throttle valve control device in an internal-combustion engine having an electronically-controlled throttle valve is provided for calculating a final target opening based on an engine operation state, which includes an accelerator depression amount, and an ISC request opening for adjusting a revolutional speed of the engine to a target revolutional speed during an idling operation, and for electronically controlling the throttle valve so as to adjust the throttle valve opening to the final target opening. The device of the present invention includes a correction section for correcting the ISC request opening based on an amount of variation in the revolutional speed of the engine when the final target opening is identical to the ISC request opening, while prohibiting the correction of the ISC request opening when the final target opening is not identical to the ISC request opening.