Patent attributes
Super retard combustion is performed in which an ignition timing is set to be after a compression top dead center and fuel is injected before the ignition timing and after the compression top dead center, at cold start or the like which requires early warming-up of a catalyst. During an idle operation without the super retard combustion, a first ISC control is executed in which a feedback control is provided for the degree of opening of a throttle and the ignition timing so that an engine speed corresponds to a target idle speed (S14). On the other hand, during the super retard combustion, a second ISC control is executed in which the control of the degree of opening of the throttle is inhibited, but the ignition timing is advanced because a catalyst may be thermally damaged when the amount of intake air is increased in accordance with an increase in load of an auxiliary device and the like (S15).
