Patent attributes
A control device for an engine includes an air-fuel ratio detector detecting an air-fuel ratio of an exhaust gas of the engine. A feedback controller performs a feedback control of an amount of a fuel injection of mixed fuel including alcohol so that the air-fuel ratio detected by the air-fuel ratio detector is come close to a target air-fuel ratio, the mixed fuel supplied from a fuel feeder. A concentration estimator estimates a concentration of the alcohol in the mixed fuel based on the air-fuel ratio of the exhaust gas and a correction amount for the amount of the fuel injection controlled by the feedback control. A malfunction determiner determines that the fuel feeder has a malfunction when the correction amount is greater than or equal to a value for a period which is longer than a first period in a second period. The second period is from a first time point when the feedback controller starts to perform the feedback control.
