Misfire detector device for internal combustion engine

A misfire detector device for internal combustion engine comprising:

• an igniter having an ignition coil which is on-off actuated by a primary current interruptor circuit, one end of the ignition coil being connected to a spark plug installed in each cylinder of an internal combustion engine;
• a peak voltage detector means which detects a peak voltage across electrodes of the spark plug after an end of spark action of the spark plug;
• a peak voltage average means which individually determines an average value of the peak voltage detected by the peak voltage detector means in each cylinder of the internal combustion engine after the end of a plurality of the spark actions of the spark plug;
• a reference value determining means which individually determines a reference value in each cylinder of the internal combustion engine on the basis of the average value determined by the peak voltage average means;
• and
• a comparator means which compares the peak voltage individually detected by the peak voltage detector means to the reference value individually determined by the reference value determining means so as to detect a misfire in each cylinder of the internal combustion engine.

A misfire detector device for internal combustion engine comprising:

• an igniter having an ignition coil which is on-off actuated by a primary current interruptor circuit, one end of the ignition coil being connected to a spark plug installed in each cylinder of an internal combustion engine;
• a peak voltage detector means which detects a peak voltage across electrodes of the spark plug after an end of spark action of the spark plug;
• a peak voltage average means which individually determines an average value of the peak voltage detected by the peak voltage detector means in each cylinder of the internal combustion engine after the end of a plurality of the spark actions of the spark plug;
• an average value averaging means which averages average values of a plurality of the cylinders except a specified cylinder so as to obtain a comparative average value;
• a comparator means which individually compares the average value of the specified cylinder determined by the peak voltage average means to the comparative average value of the average value averaging means so as to detect a misfire.