ADAPTIVE METHOD OF CYLINDER MISFIRE DETECTION IN AN INTERNAL COMBUSTION ENGINE

摘要

An adaptive method of detecting a misfiring cylinder in a spark-ignited internal combustion engine during substantially all engine operating conditions, including most no-load operation. The method includes the step of normalising an engine acceleration-independent and engine speed-independent power cycle time differential signal for a particular cylinder of the engine, obtained from consecutive power cycle time periods of an engine cycle, utilising a calibration parameter stored in the memory for the particular cylinder, to obtain a normalised power cycle time differential signal for the particular cylinder. The method also includes the step of comparing the normalised power cycle time differential signal to a misfire threshold signal stored in the memory to determine if the cyclinder is misfiring. Preferably, the misfire threshold signal is based on at least one engine operating parameter. The method also includes the step of adaptively modifying the calibration parameter stored in the memory based on the comparison.