2.8 88 Surging (Page 2/2) Rexgirl MAR 27, 02:53 PM Backfiring is a timing issue, ignition or valve. Yes, try your other distributor first. ChuckR MAR 27, 04:42 PM quote Originally posted by fierogt28: Replace the ICM with an AC Delco brand part. You can buy a tach filter from TFS or Rodney for piece of mind. If you wanna go hog wild, replace the ignition coil at the same time. No harm there. BTW, does this fiero have an old cat. convertor on it? I personally found that running the fiero without a cat. convertor was the best mod you can do without having problems. Also PO removed the cat so it is emission system free. The coil is mostly new. I will swap the distributor out with the known good. The one on it is the new star style the know good used is a stock style with the "ears". I guess I should just do it. I am a bit nervous swapping the dizzy since I dont want to wreck my timing. I have never messed with a dizzy like that before. I will also warranty the coil I just bought in case it is also bad again. The tach filter i am not that concerned with. Patrick MAR 27, 08:22 PM quote Originally posted by ChuckR: I am a bit nervous swapping the dizzy since I dont want to wreck my timing. You need to use a timing light. It's not optional. ChuckR MAR 28, 08:59 AM quote Originally posted by Patrick: You need to use a timing light. It's not optional. I bought one just for this, I also have a yellow paint marker I am going to use to highlight the damper mark and 10* mark on the scale. i also know to set timing I need to jump pins 1-2 to set diagnostic mode to stop the ECU from adjusting timing once I am ready to set timing.