| 摘要 |
PURPOSE:To diagnose the abnormality of an assist air device simply and correctly without requiring the addition of new equipment by judging the abnormality of the assist air device according to the control state of the assist air device, air-fuel ratio change, and the like during the acceleration of an internal combustion engine. CONSTITUTION:An assist air device 1 performs air injection together with fuel spray from a part in the vicinity of the nozzle hole of a fuel injection valve 26. An air-fuel ratio sensor 2 (32) is disposed at an exhaust passage 23. Further an air-fuel ratio feedback control means 4 performs the feedback control of fuel injection quantity on the basis of the detection signal of the air-fuel ratio sensor 2 so that the air-fuel ratio of an internal combustion engine 3 (21) becomes a stoichiometric air fuel ratio. In such constitution, the specified acceleration state of the internal combustion engine 3 is detected by an acceleration detecting means 5. On the other hand, the air-fuel ratio change during acceleration is detected by an air-fuel ratio change detecting means 6 on the basis of the detection signal of the air-fuel ratio sensor 2. The abnormality of the assist air device 1 is then judged by an abnormality judging means 7 according to the control state of the assist air device 1 and air-fuel ratio change during acceleration. |
