A method and system for a misfire detection acquires (301) a series of
acceleration
data (302) representative of acceleration behavior of an engine. The data
is sampled (304) to obtain acceleration data samples at a rate sufficient
to obtain up to fourth-order perturbations of the data. The samples are filtered
(322) to provide bandwidth limited samples, which are provided to at least
two channels (325, 329). The samples are pattern matched (332) in
a first channel to enhance harmonic phenomena and pattern canceled (330)
in a second channel to enhance random phenomena. Hard and random misfires are detected
(334) dependent on a magnitude of the filtered acceleration data samples.
Preferably, a third channel (335) is added to detect multiple misfires.
