Car couldn't find idle and would start then die, bucked and jerked while driving and died at stop.
Engine lite came on, ran code low voltage MAF, I got the car started with scanner attached, MAF was reading 29.5 on a steady line even on acceleration. MAF replaced, cured all but the bucking on mild/hard acceleration. Idle still searching, pulled out the idle sensor located next to the new maf, it was really dirty so I replaced it and then sprayed the throttle body screen with cleaner. Idle seems to have found a home at 650 - 700 rpm.
My instincts tell me that I might have a bad plug wire with a jerk on acceleration so I replaced the plugs and wires. No good still jerks under aload.
Fuel problem possible, hooked up the pressure gauge to the rail and it reads a consistant 44psi even when it runs and when it'* shut off it spikes to 55psi.
I don't see any cracks at the coil pack/ignition module nor do I find any vacuum lines off/or leaking
It does seem that most of the Jerks take place upon mild/hard accelleration and the rpm is at 1700-2000 rpm. Havn't seen or had many jerks below or above that range. Possibly a bad spot in the Throttle Position Censor?
150,000 miles on the car, don't know if the timing belt was ever changed, to sloppy and this causes the computer to not know what it should do?
Any help appreciated

Personally it sounds like a misfire still..does your check engine light flash at all?

no codes or flashing lights on at all, yesterday drove it like an old guy to church, it didn't buck once. later in the day had to go to next town over and it had rained, started bucking like crazy, almost reminded me of my son in laws 90 something tbird that the transmission tried to down and up shift any time it wanted after a rain storm. Wonder if the 2000 pa has electronic transmission and the plug in is getting and staying wet.
I can floor the accelerator and the vehicle will move out and engine will reach red line on tach with out so much as a buck, miss or anything,
but it is setting no codes and no flashing lights
thanks for the reply

is your speedo doing anything flakey when this happens? any corrosion on the coil posts or the tabs the coils plug into?

Sure sounds like a misfire. The comment about being related to rain makes me think it is a bad plug wire. Take a spray bottle and spray water around the coils, wires and plugs with the engine running and when it is dark out. Look for any arcing (blue lights).

Took the car on the interstate last night, several bucks around 1700 rpm and with the cruise on at 65mph car runs fine until a hill and the car needs to accellerate then it bucks, at 2000 rpm and 70 mph car goes into constant buck mode. but you can floor it and it comes right out of it. This one sure has me puzzled. have noticed that the temp gauge is not getting up to temp like it has all summer, running about 187 degrees and doesn't seem to get above that on the road, wonder if the thermostat is stuck open?
Also engine started and died again this morning and then restarted and idled very errattic but came out of it as it warmed up?
any clues?

Just got back from a friend who runs his own shop. He put his snap on scanner on the car and I drove while he watched the scanner for misfire info. Seemed like every cylinder misfired during the 15 minute road test. He did find out that the 1/4 coil had an external crack, but when we replaced it with one he had laying around it made no difference.
He ordered a throttle position sensor and we put it on, but nothing changed
Did I say that I replaced the MAP this morning after I was checking it and the top part came off in my hand, that didn't change anything either.
So what next. all of this seems to still happens between 1700 - 2000 rpm
Ignition module seems like the most likely thing to check next

I've heard of the Ignition control modules going bad blowing coils and causing misfires. I strongly believe this is what'* causing mine to stutter at 1700-2400 (03') not quite bucking like yours but stuttering nonetheless. The ICM is what the coils sit on top of on the 3800. See if your mechanic friend has one sitting on his parts shelf to swap and drive for a bit.

Well, today I picked up a new ignition control module and installed it. No change, still bucks when accellerating thru the 1700-2000 rpm spot. I also took the advise to get rid of the spark plug metal sleeves. that didn't help either.
Finally decided to take the car to the local buick dealer, as I explained the symptoms he said that he couldn't think of anything else to try. now I'm worried. This car runs way to good to junk, what power this think has when you drop the hammer on it.

latest update
notice car temp was running lower then normal, removed and replace temp cool sensor, and thermostat, now car is back to where it should be for temp, not sure if the cooling fans are coming on or not.
decided to unplug the sensors one by one to see if I got a better running car, when I unplugged the new maf, I got a smooth idle and the stumble is gone. I hooked up my actron scanner and the signal is or should I say varies with rpm. wonder if I have a bad connection or wire to the pcm? or if I just have a bad replacement part?