vibration/missfire September 15, 2006, 12:03:11 AM 1987 3.8L tbird. I get a vibration that feels like a missfire. Thought it was ujoints, changed them and it got better. Happens when I let off the gas to reduce speed, and at speeds around 65-70. Distributor, wires, coil, and plugs are all new. help. Quote Selected