Take a screwdriver with a good rubber or wood handle, definetly not metal or plastic. Ok, now stick the end of the screwdriver in the distibuter holes(wire holes) and have someone try to start the car, then slowly pull the screwdriver out of the dist. and see if there is any arc.(blue spark) It's best to do this inside a garage with the lights off or at night. For extra safety I suggest wearing rubber gloves. Even if it does shock you it won't do much harm.(known by experience) hope this helps. A dist can go bad anytime, all those tiny parts in their can easily get screwed up.