The other day after a long drve (240 miles) my old brick started to missfire. Soon after that she died completely. after a tow home, I discovered (in the daylight) that the distributor rotor was fried. It was as though there had been electrical arcing from the center pole to the tip of the rotor which cooked the plastic. There was no connection between the center of the rotor and the tip. I replaced the rotor and the cap for good measure and she fired up. I was wondering what could have caused this. I know that commonly mositure can be the source of carbon tracking and other malaties in the cap area, but what makes this particular thing occur, and how can it be avoided in the future? This cap was approximately 6 months old and had about 10k miles on it. please advise.