Misfire detection by acceleration discrimination.

A SYSTEM AND METHOD FOR TO DETECT THE PRESENCE OF A STATE OF FAILURE ON THROUGH THE INTERPRETATION OF THE SPECTRUM ACTIVITY OF A MOTOR RUNNING including a device (309, 313) for measuring a characteristic, preferably a feature of aCCELERATION, INDICATIVE OF BEHAVIOR engine running. A FILTER PROGRAMMABLE (701) DEPENDENT OF A CERTAIN ENGINE SPEED (335) PROVIDES filtered acceleration signal (703) responsive to an acceleration signal (317) PROVIDED BY THE ACCELERATION measuring device (309, 313). DEVICE spectral discrimination (319), preferably a digital filter, receive filtered acceleration signal (703) provided by the filter programmable (710). The digital filter (319) PROVIDES A SIGNAL ON NORMAL (321), corresponding to the energy ESPECTRAL ATTRIBUTABLE TO A portion of the composite signal (317) REPRESENTATIVE OF A STATE OF ENCENDIDONORMAL ENGINE RUNNING, AND A SIGN OF FAILURE ON (323), corresponding to the energy ESPECTRAL ATTRIBUTABLE TO ANOTHER pORTION the composite signal (317) STATE REPRESENTATIVE OF A FAILURE ON THE ENGINE RUNNING. A comparator (325) PROVIDES E indicates a state of FAILURE ON (327) MAGNITUDE WHEN A SIGNAL FAILURE ON (323) exceeds a magnitude SIGNAL ON NORMAL (321).