| 摘要 |
<P>PROBLEM TO BE SOLVED: To properly determine intermittent misfire of an internal combustion engine having a plurality of cylinders or more. <P>SOLUTION: This misfire determining device calculates sum Nxdint of rotation fluctuation as sum of rotation fluctuation Nxd being a fluctuation value of rotational speed N of a crank shaft per crank angle 120°CA corresponding to ignition timing of each cylinder of six-cylinder engine and preceding rotation fluctuation Nxd to the rotation fluctuation Nxd by crank angle 360°CA (S130) and determines that intermittent misfire occurs when the calculated sum Nxdint of rotation fluctuation is larger than a determined value Nref1 corresponding to the rotational speed N of the crank shaft and amount Ga of suction air per rotation (S150) and a ratio of the preceding sum Nxdint (2) of rotation fluctuation to the sum of rotation fluctuation Nxdint (3) is less than a determined value Nref2 (S180). Consequently, it is possible to determine intermittent misfire of the engine properly. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
