System to determine the misfire of an engine.

A METHOD AND SYSTEM FOR DETERMINING A misfire IN A MOTOR FOR MEASURING THE SPEED CRANK ANGLE, AND PROVIDES A SPEED SIGNAL FROM THE ANGLE AS A MEASURE engine crankshaft (403). An acceleration signal FILTERED SIGNAL DEPENDENT SPEED ENGINE CRANK ANGLE AND INDEPENDENT INFORMATION NORMAL COMBUSTION AND OTHER EFFECTS OBTAINED BY ES filter (405). When the signal filtered acceleration EXCEED THE DEPENDENT AT LEAST ONE OF THE FOLLOWING ENTRY: engine speed, engine load, OR MOTOR TEMPERATURE (711) OCCURS a misfire. Preferably, prior to misfire, the filtered ACCELERATION signal (701) IS PROVEN THROUGHOUT an initial period of crankshaft rotation ENGINE FOR A FIRST POINT OF INFORMATION (703), AND ALONG A SECOND PERIOD ROTATION engine crankshaft FOR A SECOND POINT OF INFORMATION (707), AND ALONG A THIRD PERIOD OF ROTATION FOR ENGINE cRANK A THIRD POINT OF INFORMATION (705) .Then a calculation middle between the first and third POINT OF INFORMATION IS oBTAINED FROM THE SECOND POINT OF INFORMATION ALSO obtaining an acceleration signal COMBINED (511). THEN INDICATED FAILURE (517) when the acceleration signal EXCEEDS THE COMBINED INLET (513). Preferably, this TEST filtered acceleration signal is continuously, AND TEST FIRST, SECOND AND THIRD POINT OF INFORMATION BY SPREADING two rotations of the engine crankshaft.