| 摘要 |
A method of detecting spark plug fouling in an internal combustion engine is provided. The method comprises calculating an integration value of discharge current (i2) flowing between electrodes (17a-17b) of a spark plug (17) during a period of a spark discharge and judging if the calculated discharge current integration value is smaller than an integration value criterion. The integration value criterion is set at such a value that can discriminate between normal discharge and interior jumping (i.e., jumping due to fouling). When the calculated discharge current integration value is smaller than the integration value criterion, it is judged that the spark plug has been fouled. By this, it becomes possible to detect spark plug fouling before the center electrodes (17a-17b) of the spark plug (17) are short-circuited and disabled to generate spark discharge, i.e., before the spark plug (17) is fouled to such an extend as to cause a misfire. An ignition system (1) for detecting spark plug fouling is also provided. <IMAGE> |
