| 摘要 |
PURPOSE:To prevent exhaust of unburnt gas by controlling an operation state in a way that a relation between an exhaust gas temperature and a catalyst temperature during normal operation of an internal combustion engine is stored from an operation state serving as a parameter and a failure in ignition state is discriminated through comparison with an actual operation period. CONSTITUTION:A control device 8 effects following operation. An exhaust gas temperature TH by an exhaust gas temperature 20 and a catalyst temperature TS by a catalyst temperature sensor 21 are inputted, a temperature ratio CMP = TS/TH is computed, and from the number of revolutions and filling efficiency, the operation zone of an engine is discriminated. In this operation zone, a ratio CMPX between the exhaust temperature and the catalyst temperature during normal operation of an engine is determined through retrieve of map data stored in a ROM 82 or an RAM 83 to determine a difference between CMP and CMPX. Since, in a failure in ignition state, the value of the CMP is increased to a value higher than that during normal operation, when a difference between CMP and CMPX exceeds a fluctuation range , it is decided that failure in ignition occurs, injection of fuel is stopped, and a lamp 22 is lighted ON. |
