Patent ID: 7024303

Claim:
A method for detecting misfiring in an internal combustion engine ( 1 ) by analysing the angular acceleration (acc) of the drive shaft ( 4 ); the method comprising the steps of: estimating the value (acc) of the angular acceleration of the drive shaft ( 4 ) at predetermined angular positions of this drive shaft ( 4 ); comparing the absolute value (acc) of the angular acceleration of the drive shaft ( 4 ) with a predetermined threshold value (S); detecting the presence of a misfire if the absolute value (acc) of the angular acceleration of the drive shaft ( 4 ) is greater than the predetermined threshold value (S); filtering, when the presence of a misfire is detected, when an absolute value (acc) of the angular acceleration of the drive shaft ( 4 ) exceeds the threshold value (S), a set of values (acc) of the angular acceleration of the drive shaft ( 4 ) subsequent to the value (acc) of the angular acceleration of the drive shaft ( 4 ) at which the misfire has been detected to eliminate the oscillation component generated by the misfire with respect to the value (acc) of the angular acceleration of the drive shaft ( 4 ); and comparing only the filtered values (acc) of the angular acceleration of the drive shaft ( 4 ) with the threshold value (S) to detect the presence of any further misfires subsequent to the misfire detected.