| 摘要 |
<P>PROBLEM TO BE SOLVED: To specify abnormal fuel injection valve when abnormality of a fuel injection valve occurs in a system having two fuel injection valves disposed to each cylinder of an engine. <P>SOLUTION: When abnormality of air-fuel ratio occurs during engine operation, a cylinder in which abnormality of air-fuel ratio occurs is specified, injection ratio change control gradually changing ratio of command injection quantities of the two fuel injection valves 21 while keeping total of command injection quantities of the two fuel injection valves 21 constant in the abnormal cylinder, and the abnormal fuel injection valve 21 is specified with using learning value of air-fuel ratio F/B correction quantity. Since change behavior of actual total injection quantity of the two fuel injection valves 21 is different and change behavior of air-fuel ratio is different with depending on whether fuel injection valve 21 is abnormal when injection ratio change control is executed under same conditions, the abnormal fuel injection valve 21 can be specified by evaluating learning value of the air-fuel ratio F/B correction quantity based on output of an exhaust gas sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT |
