| 摘要 |
PROBLEM TO BE SOLVED: To speedily detect a state of failure of an assist air supply mechanism without complication of constitution and to externally display the state of failure. SOLUTION: Whether a working state of an engine is in a stationary state or not is judged by an engine working state detection means 20, and when it is in the stationary state, opening and closing work of an assist air passage to supply assist air to an air assist injector 5 is carried out (opening and closing means control part 24). An air-fuel ratio during this opening and closing work is detected by an air-fuel ratio detection means 4, and whether failure is caused in an assist air supply mechanism or not is judged in accordance with a change of this air-fuel ratio by a failure judgement part 26. That is, when the air-fuel ratio is changed in correspondence with the opening and closing work, it is judged as a normal state, and when it is not changed, it is judged as a state of failure. |
