[CHRIS DAMSCH]

I chased a similar issue in my SPF all summer. I was left stranded more than once. I finally narrowed it down to the msd 6am was intermittedly working. The car would start fine cold and run for as long as you wanted until you **** it off. It wouldn't restart until it cooled down for hours. Finally the last time it just never restarted.
When it won't restart, check for spark(when hot). This drove me crazy all year. Put a new box in and it starts easier than ever before. Makes me wonder how long the box was acting up.