System and method for filtering a misfire detecting data stream to yield

Abstract

System and method for filtering a misfire data stream having numerical values that indicate whether a firing of a cylinder was a misfire or a proper firing, to yield an optimum measurement misfire-rate for accurate and rapid determination of whether an engine is misfiring beyond a threshold level. The method includes measuring firings of the cylinder during operation of the engine to produce measured cylinder firing signals, processing the measured cylinder firing signals received to produce a current misfire detection data stream of first and second logic signals, wherein the first logic signals indicate a current misfire condition and the second logic signals indicate a current normal firing of the engine, combining the current misfire detection data stream with previously detected and stored measured data representing an engine misfire rate, replacing the previously stored measured data by the combined current and previously stored data to produce a misfire rate output measurement, storing threshold values, comparing the combined current and previously stored data and the stored threshold values, generating an actuation signal if the combined current and previously stored data signal exceeds the stored threshold values, and indicating a misfire condition in the engine upon receiving the actuation signal.