Patent ID: 7207317

Claim:
An engine control system for controlling an engine in which a fuel is supplied from a fuel supply system and which is ignited by an ignition system, comprising: a throttle sensor which detects an opening degree of a throttle valve of said engine; detonation detection means which outputs a detonation detection signal which level varies according to strength of detonation when detonation occurs in said engine; judgment level setting means which gives a judgment level being compared to the level of said detonation detection signal in order to judge whether the detonation which is necessary to be inhibited occurs in said engine; enrich control means which controls said fuel supply system so that an air-fuel ratio of air-fuel mixture being supplied to said engine is changed to a rich-side in order to control the detonation when the level of said detonation detection signal is equal to or more than the judgment level; and detonation control ignition control means which controls said ignition system so as to intermittently stop an ignition operation of said engine for controlling the detonation when said detonation detection signal is equal to or more than the judgment level even if the air-fuel ratio is enriched to the limit by said enrich control means, wherein said judgment level setting means is comprised so that the judgment level is set as a first value when the opening degree of the throttle valve detected by said throttle sensor is less than a set opening degree and that the judgment level is set as a second value which is larger than said first value when the opening degree of the throttle value detected by said throttle sensor is equal to or more than the set opening degree.