Abstract

Disclosed is an electronic automatic control method and system for controlling an air flow rate for an internal combustion engine of an automotive vehicle. The system includes an open loop control and a feedback control which are selectively effected corresponding to engine condition. The system includes an engine or temperature range within which the system controls engine speed. The given temperature range corresponds to a normal ambient temperature range so as to improve warming up efficiency upon starting engine under cold engine conditions. The system further includes a means for determining a feedback control condition to effect feedback control at a specific engine condition. In the feedback condition, the variable rate of a control duty cycle pulse which is applied to an electrically operative air flow rate adjusting means, is determined corresponding to an actual engine speed and a difference between the actual engine speed and a reference engine speed determined corresponding to the engine or coolant temperature.