METHOD AND AN APPARATUS FOR CONTROLLING THE AIR-FUEL RATIO IN AN INTERNAL COMBUSTION ENGINE

The pulse-width of the fuel injection signal is controlled, depending upon the running speed and the intake manifold pressure, and corrected by the transient correction factor, which is determined in accordance with the transient operating condition, and the A/F correction factor, which is determined the air-fuel ratio condition. The map used for obtaining the transient correction factor from the transient operating condition is corrected depending upon the converging state of the A/F correction factor by the learning control operation.