I have a 95 impala ss that recently had problems idling only when it rained. I changed my optispark distributor and all has been well for about two months. Last week it started having the same hesitating(like its missing or something)ALL the time. The second day of this continuos prob it shook real bad as if it was going to die, so i pulled into a gas station and cut her off. It would NOT start after that. I replaced the distributor and it is still doing the same thing. After toying with the ignition coil(with a screw driver while cranking VERY DANGEROUS ) it was firing only when it wanted to, when i believe it should be a constant pulse. Could my ignition coil or module be causing this, or could my new distributor be faulty, or maybe even something else? I would GREATLY appreciate any help, im a college kid in oklahoma who is running out of money to get this darn thing running right before next semester. THANKS EVERYONE!!!!!