| 摘要 |
PURPOSE:To prevent a fuel injection quantity from excessively increasing after finish of a fuel injection cut off, by increasing the integration time constant to be longer for air fuel ratio feedback during the time an output of an air fuel ratio sensor initially changes to an overrich signal after the finish of the fuel injection cut off. CONSTITUTION:After finishing a fuel injection cut off, an output of an air fuel ratio sensor initially changed to an overrich signal is detected in a step 74, and during the time from this detection to resetting, a flag B is set to ''1''. During the time with the flag B in ''1'', an excess of integration is set to l' in a step 77, while during the time with the flag B in ''0'', the excess of integration is set to l in a step 78. Further being the relation where l'<l, the integration time constant of the air fuel ratio sensor during the time where B=1 is longer as compared with that of the sensor during the time where B=0. In this way, a fuel injection quantity can be prevented from excessively increasing after finishing the fuel cut off. |
