IC engine misfire detection method

摘要

In the first stage of the method, there is continuous detection of RPM variations and production of a value for erratic running dependent upon the detected values. In the second stage the summation of several values is produced consecutively during a working cycle of the engine, and in a third stage the summation result is tested to check wether it falls within the set range. In a fourth stage, misfire detection is discarded if summation result is not within the set range. The summation result is low-pass filtered, and there is a test that the filtered result is within set range. The absolute sum of summation results is produced and compared with a set threshold value after low-pass filtration. Misfire values are subjected to dynamic correction.