Method for controlling the air-fuel ratio

摘要

Whilst an internal combustion engine is operating in the idling state or whilst the throttle valve is opened by less than a specified amount, a mean value of a correction variable is calculated for the air-fuel ratio. When this mean value departs from a predetermined range, an error correction value is subtracted from the correction variable of the air-fuel ratio or added to the correction variable so that the mean value can be kept in the said, predetermined range, thereby allowing a stabilised or constant air-fuel ratio to be maintained for a long period of time.