Idle speed control device for engine

摘要

An engine control device has an idle speed control of an engine by an ignition timing control and an idle speed control by air-by-fuel ratio feedback. This engine control device detects roughness caused by a torque change on the basis of a change in angular velocity of a crank shift, sets a control gain depending on the roughness, reflects the control gain on the idle speed control by the ignition timing control, thereby harmonizing the idle speed control of the engine by the ignition timing control with the idle speed control by the air-by-fuel ratio feedback. <IMAGE>