Idling speed control apparatus for internal combustion engine

摘要

To provide an idling speed control apparatus for an internal combustion engine which can perform positioning of a step motor accurately without additionally providing a battery. The idling speed control apparatus includes storage means 11 for storing an engine stop step number Pstop, means for driving the step motor based on a target position step number Pt which represents a target position of the step motor and a present position step number Px which represents the present position of the step motor, and idling state discrimination means 52 for discriminating whether or not the idling is in a steady state. Upon starting of the engine, the engine stop step number Pstop is registered as the present position step number, and when it is discriminated that the idling is in a steady state, the present position step number is rewritten into a reference step number which is a predetermined constant and the present position step number is stored as the idling reference step number.