What Does It Mean If A Spark Plug Is Black?

What Does It Mean If A Spark Plug Is Black? Black, dry soot on the electrodes and insulator tip indicates a carbon-fouled plug. This can be caused by a dirty air filter, excessive driving at low speeds, too rich of a fuel/air mixture or idling your vehicle for too long. Should a spark plug be … Continue reading What Does It Mean If A Spark Plug Is Black?