[CHRIS DAMSCH]

This summer my MSD 6al was working on and off. Sometimes it ran like a champ and other times no spark. I did MSD's tests off of their website. Sometimes it worked, other times it didn't. Finally, it just ended up the box completely gave up. Put in a new ignition box and the car fires right up and runs perfect.

Maybe it's an intermitted problem with the box?
Does the car crank, but just no spark?