I have a 1995 Buick Regal the 3.8l V6. After Recently Changing My Oil and Air Filter and spark plugs, If I Try to Accelerate the car kinda hesitates gains power and hesitates again etc. If kinda feels like its not getting gas then it kicks in, at freeway speeds the car runs fine except if I try to accelerate to pass a car or climb a hill then it hesitates, I pulled the plugs again to make sure they were gaped properly, they were, At idle speed the car runs PERFECTLY FINE, and when the car engine is COLD I could stomp on it and it will perform Perfectly fine so Im kinda stumped. The Car only has 85k original miles and is in mint condition
You need to get a fuel pressure reading and have your ignition control module tested. If both pass a back pressure test might be in order
June, 30, 2012 AT 7:13 AM
Iam thinking possibly a plugged cat makes more sense then the igniton since it doesnt seem to back fire or miss.
June, 30, 2012 AT 12:25 PM
What kind of plugs did u use? I just fixed a car yesterday it was a 93 bonneville 3.8 and they had just put plugs in but they tried to cut corners and used a bosh platinum plug and because of the shape of the electrode the car would barely run. I replaced them with come AC Delco # 41-940 double platinum plug and the car is fine
June, 30, 2012 AT 6:52 PM
The original plugs are ac delco I replaced them with autolite 606. When the engine is cold the car runs like a brand new vehicle Lots of power but the stuttering starts happening when it reaches operating temp. It sounds like an exhaust fluttering noise and the car kinda bucks like when your trying to teach someone to drive a stick and they dont qiute get the pedal release right know what I mean. Thanks so much for the help on this, I usually try to do my repairs myself, I DID buy the cheapest plugs, maybe step one would be to put in better ones, thank you all for the replies
June, 30, 2012 AT 6:58 PM
Saturntech, My first thought was that the Cat was plugged or the fuel pump is failing when I press hard on the gas, cause at 4k rpm the car immediately loses pressure kinda like a rev limiter but a complete pressure lose
June, 30, 2012 AT 11:35 PM
At 4k in park the engine turns off and on over and over again?If so sounds like a rev limter why dont you have a back pressure test done when its hot and acting up to rule out a plugged cat?
July, 1, 2012 AT 7:30 PM
Yeah Im going to do the back pressure test, in park at 4k the car doesnt turn off it just loses compression, I looked at the Cat while reving the engine and at 4k rpm I see the Cat shaking real hard then it goes back to normal, thank you all so much for the help
July, 1, 2012 AT 9:08 PM
Yeah you do a back pressure test in park. Keep us posted on what you find.