1995 Cutlass running rough (again)

Have 95 Cutlass Supreme with 120K and a couple of months ago it started running a bit rough and hesitated a good bit on acceleration (weak acceleration also). I changed the plugs, plug wires, clean the throttle body & IAC, changed the O2 sensor and changed the PCV valve. All this had very little effect on the overall performance so I went ahead and took it the shop. They replace a coil pack and that got rid of the rough running problem, but the hesitation was still there. I took it back and they said I needed new plug wires even though I had recently changed them. I went ahead and bought AC plug wires and installed them. I test drove the car quite a bit and it still had the hesitation so I figured I would take it back to the shop. The morning I was planning on taking it to the shop it ran fine so I didn't take it. After than it the hesitaion would show up again every now an then for a few more weeks. For the last couple of days the car is running the same as it was before I ever took it to the shop. It runs rough (vibration at idle and during acceleration) and has rather weak acceleration. I plan on taking it back to the shop soon, but thought I would see if anyone had any ideas what might be causing the problem.

Thanks

Having the same problem with my 1995 cierra. Have you found out what the problem was.

Thanks.
Terry

did you find out what the problem was with your 1995 cutlass, having the same problem with mine.

Terry

another coil pack went bad (2 down 1 to go) and some of the plug wires were not routed properly. After having the coil pack replaced and rerouting the plug wires the car runs better than it has in a few years.

Check your TPS (throttle position sensor) and replace your IAC valve its right above the TPS on your throttle body. The IAC valve is only like 12 bucks no biggie. Other than that have the code checked on your car. I had a problem like that and turns out that I forgot to plug in my air temp charge sensor (it's on the air intake). If you ran the car without that plugged in then the ECU will get a bad reading from the O2 sensor making the car run too rich. So check it out and if you still have the problem I'm sorry you have drained my brain :)

I was having similar problems with my 1990... The running rough, rough idling, etc.

I took it to get an oil change, and they noticed the rough idling, said it would be a good idea to get a Fuel Injector Service done, and then take it to Chevron for a tank of the Uber-High octane fuel, and take it out on the highway for a bit.

Take this all with a grain of salt, I'm no car expert, and haven't had a chance to drive it much since I had this done yesterday because I rear-ended someone on my way home... (Stupid rain, stupid oily roads... :( :( :( )...

At any rate, the service was only like $50 CDN, and I'm sure it can't hurt anyways. Especially if it actually does fix the problem... I had it done at one of the Pennzoil places.

I had problems with starting rough and not staying running in the mornings-the local shop pulled the plenum on my '95 and found a collapsed vacum line causing the idle and starting problem. Now it runs much better, starts, and idles great. I even have a better brake pedal.
It was way costly-that is the downside! So maybe this might help I hope!
D

you can get a full vacum line system for like 20-30 bucks at your local parts store.