Hello all,

I've seen this post several time but never found a solution. I have a misfire on acceleration, I have already changed O2 sensor, Bosch plugs, Delco wires, MAF, coils and control module. Could it be the TPS, EGR, Clogged Cat??? Seems to get better as RPM's increase. If I baby it it seems hard to notice but still there, just the more you push the gas the worse it gets. I know other people have solved this but I have not found any posts. I hate to take it to the local dealer they told my wife it would be $395 to change the plugs and wires and would not say for sure that would fix it. Good thing I did it myself. Any help is greatly appeciated

I had sort of this issue with my PA. I only had to change the plugs and one of the coil packs was corroded. It is possibly you could have a vacuum leak or there is a problem with the timing advance. The timing may not be adjusting fast enough for the engine to keep up during a hard acceleration. That would be a reason why when you baby it you dont notice it as much. Look into the timing controls. I just got my PA and havent been able to get that much time under the hood so I really wouldnt be able to tell you what to look at exactly or what kind of timing advance you have. That would be where i would start. Also check to make sure that the egr is not clogged. I got the advise in my post and I cleaned mine when I replaced the coil and the plugs. hope this helped or gave you an idea of where to go next with it.

I have a '97 PA Ultra, with very similar symptoms. I got a code of p0304, which I believe translates into a " misfire in cylinder #4 " can anyone elaborate on this ?

I just did some research and the P0304 is a misfire code. I would recommend checking the coil pack on that plug. On mine the 3,6 coil was corroded and when I tried to clean it the situation got worse and the car actually started backfiring instead of just missing. I replaced the plugs all the way around. I also found that the gap was off in the plugs. So with the new plugs and that coil pack the car is running great. I also cleaned the EGR valve. I would pull the plug on that cylinder and see what is going on. You could also be having a problem with the fuel injector on that cylinder.

What chevygirl suggests is good advise but I'll suggest putting in AC plugs also,good luck and post back.

Your just throwing parts at this car which all sound logical, but has not produced results Suggest you have it scaned for codes. It may either be the crankshaft or cam shaft sensor that is causing the misfire. It sounds like a timing issue.

Is it possible that there is anti-freeze leeking into cyl.#4, throught the upper intake manifold plenum ? This was the possible diagnosis my brother in-law gave last night. He said that he has had this prob.,with his La Sabre, and that he replaced it himself.Is the "check engine soon" light flashing? If so he said don't drive it and get repaired before it locks up.

Can anyone shed some insight on this possibility.I drove my car(97'PA Ultra) into the garage and it will stay there until I find out for certain
HELP

nevee1,If its loosing antifreeze its possible,but if it isn't its not where you should be looking.