Engine idling speed control method and apparatus

摘要

An engine speed control method and apparatus employs at least two basic control variable maps comprising a first basic control variable map for determining the desired air flow to an internal combustion engine in accordance with the warming conditions of the engine during the starting period and a second basic control variable map for determining the desired air flow in accordance with the warming conditions of the engine after the starting period, and the maps are used selectively in accordance with the warming conditions of the engine. Upon change-over from the control according to one map to the control according to the other map, the air flow is varied gradually at intervals of predetermined engine revolutions or a predetermined period of time so as to effect the change-over to the control according to the desired map. During the idling operation after the engine has been warmed up sufficiently, the difference between each of the desired idling speeds preliminarily established in correspondence to the operating conditions of the engine and the actual idling speed is detected and the required correction values of the basic control variable for controlling the air flow are computed and stored thereby controlling the idling speed of the engine.