msd 6

have changed coils , first thing I thot about , also many other changes , runs like a 505 should till I hit a bump , then dies ...but will restart , suspect a wire grounding some where when I hit that bump...
Like I have seen, every racer has a extra box in their trailer. There's a reason for that yet many here have used MSD systems on their street cars for years with no issues. It's probably a box.