ENGINE CONTROL SYSTEM

Accurate detection of abnormal combustion is enabled even in an engine in which a combustion chamber has only one ignition plug provided with an ion-current detection function. An engine control system according to the invention is provided with an ion detector(4) for detecting ions generated during combustion, and a control unit (20) including a combustion-state determination unit for determining on whether the combustion state of the engine is either a normal combustion or an abnormal combustion on the basis of a time-length (Δt) from a fall-time of an ignition-control signal (4h) to a rise-time of an ion-signal (4g) outputted from the ion detector.