Abstract: The disclosure is directed to a control device for an internal combustion engine for a motor vehicle such as an automobile or the like, having a control valve disposed in a by-pass passage for opening and shutting the by-pass passage which communicates the upstream side and the downstream side of an intake passage by by-passing a throttle valve, in which the engine speed in idling operating condition is controlled to a target speed. This control device is characterized in that the ignition timing is rather advanced than ordinary idling ignition timing during a certain period from the instance when the engine has entered into the idling operating condition after having received a signal detecting the idling operating condition of the engine.

Abstract: An internal combustion engine has an air-fuel ratio control system, an exhaust gas recirculation system and an ignition system. At least one of the systems is adjusted when the intake air temperature is very high so that fast combustion is suppressed. The adjustment is effective to prevent detonation or similar unusual combustion which may occur under a very high temperature of the intake air.