| 摘要 |
PURPOSE:To prevent occurrence of an undesirable engine stall caused by change of characteristics of a sensor used for feedback control of an air-fuel ratio. CONSTITUTION:In a internal combustion engine, a feedback factor FAF indicated by a line (3) is obtained correspondingly to an air-fuel ratio indicated by a line (2), which is detected by an oxygen density sensor, and a fuel injection amount TAU indicated by a line (6) is corrected. When inactive condition of the sensor is detected based on lowering of a sensor temperature caused by long-time idling, feedback controlling is suspended. At this time, value DS is added to a Duty of a flow passage control valve of an idling bypass passage indicated by a line (7) for a predetermined time. It is thus possible of surely prevent occurrence of engine stall which be caused by abrupt change of the feedback factor FAF. |
