1992 Pontiac Bonneville • 6 cylinder FWD Automatic • 140,000 miles

1992 Pontiac Bonniville SSEI runs but has a miss to it. Checked all plugs and wires and they are good. Used a spark tester as well and there is juice from coils to all 6 plugs great spark. When she hits overdrive is shutters pretty good as well PLEASE HELP!
January 8, 2011.

Changed plugs, wires, ignition coils, and modual, MAP sensor, MAF sensor, changed Injectors everything! I put a spark tester in between the plug and the wire and good spark all around still says number 5 cly! When u drive it its great all the way up until overdrive, once in it shakes real good till about 65 then u can barly notice it I am SO CONFUSED! I am VERY knowledgeable with ALL GM cars and trucks and this is honestly a first!

Jan 11, 2011.
I have a 96 SSei, transmission done 2 years ago because it started to jerk in OD, so thought it was tranny. 2 years later, internal harness burned out and replaced all solenoids incl. TCC. Also have New TPS and idle control sensor. When it hits OD, it jerks and when I accelerate hard, the engine light flashes. The tranny shop says it's not the trans work done, but that the car is missing?

Jan 3, 2013.