oookay.. i have a 94 bonnie SE, with 207,000K on it. i bout it from a car dealer who "stretched the truth" about the car when he sold it to me. it was 1900.00 and I thought it was a good deal because i am a huge pontiac fan, also i heard amazing things about the 3800 V6.and of course the working AC, was deff. a strong selling point being that my current car didnt have it and it was hot as all H*LL. so back to the story, when i got the car the serv. eng. soon light was on, he told me that it was the O2 sensor, the car was also running pretty rough, he then told me that the engine had been rebiult at one time. he was unsure what the mileage was that it was rebiult at, but he would try to find the paper wk.(never was produced) SO! as i drove this car, i have discoverd that the heater core was bypassed, the motor was not rebiult, never touched, all the motor mounts along with trans mounts needed to be replaced, the harmonic bal. also went out, water pump was replaced, crank sensor also replaced, TPS replaced, trans flush, fuel filter replaced, air filter, O2 sensor, Cat Conv, Rad rebiuld, thermostat, all replaced. I have also taken the throttle body off and cleaned every sensor on it, along with the throttle body itself, i must say it was really bad looking, but when i was done it was good as new..serv eng. soon light has gone off.. no codes.. i have changed the plugs wires, and all coils, along with vaccum lines.. now that i am putting all this on here.. it sure is alot of time and money i have put into this car. . i love the car and do not have the slightest urge to get rid of it, now i am stuck with this missing problem that i have been trying to correct this whole time, i do not understand what i have not done to fix it, the final problem that i am having is when the car has been drivin and you come to a stop the car seems to develop a miss that makes the whole car shake. but if you get stuck at a red light for like say about two cycles and your just idling, when you go to take off again, there is a loss of power, sputtering, feels like it is not getting enough fuel, or the fuel deliv. is intermet. but as i contune to drive at one speed (45-50) for three or so min. it seems to correct itself. untill the next time i get stuck where i have to just sit, accompanied with this, when it is sputtering and i give it say 75% throttle, there is a rattling type of sound coming from the engine, but this also goes away when the sputtering goes away.... i know that this is alot to take in, i have a habbit of rambling.. needless to say, with all the parts that i have replaced, i have no clue what to even look at next,, i would like to have the "getup and go" that my car is supposed to have, but i just cant seem to find the problem, there are no "dummy" lights on, and i have spent hours on end working on it.. im only 24 and not a mechanic.. But cars have always been a passion for me, so im pretty knowlegeable when it comes to repairs.. anything yall can add, or suggest that i look into would be outstanding.. i know that yall are tired from all this reading so i understand if you have to take a nap before responding.. take care. thanks alot Peace!

**UPDATE** i took off the throttle body again to check the TPS again..i know if it is not just right it will make that car run alittle funny.. i do not have a voltage meter ( we aint that high tech here in TX hehe) i put the throttle body back on and now there seems to be coolant leaking.. it appears to me that its leaking from where the throttle body connects to the intake,, but its not coming out of the throttle body, its coming i guess it would be out of the manifold?.. if you are standing in front of the car looking at the engine,, the coolant is coming out of the far right corner on the manifold, just right after the thermostat housing closest to the throttle body ..it did the same thing the last time it took the TB off.. but the leak aparently stopped on its own last time.. now it seems that its not stopping.. its not gushing out or anything.. but its noticable enough to where i can tell its damp between the top intake manifold and the engine block. but yea i dont think that it is gonna stop on its own this time.. i hope that the intake mani. gasket didnt go out.. im not That good of a shade tree mechanic!

that kinda sounds like what happened to my honda prelude...but that happened to me cause my trans was goin out...i hope its not the same reason for you

Welcome to the club. Just a thought here. Check your injectors and make sure you have all the same color injectors. I had 5 white ones and one red one. I knew something was wrong with the picture as I also had a sputter and a buck when the lockup kicked in. I changed the injector (which was a completely different style) with a boneyard one and that took care of it. You may want to check your fuel pressure if you are getting a knock. That knock could be detination and could kill your motor if thats the case. You could have a fuel pump getting weak. I am not an expert but these are things I would check. One of the resident gearheads should chime in soon.

thanks for your reply...i will def. look into that,,, what exactly is "lockup" in a trans. i know that mine sometimes goes into OD but only for a short period of time. about 5 mins when i get on the highway.. but after 5 min it goes out of overdrive.. never to go back in for the rest of the time i have the car running.. i know one thing is for sure.. the fuel system is the only thing that i have not done anything to,, so it is most likely the culprit..

Hi.. Welcome to the club..

Before any good diagnosis can occur (nothing against Blwn..but I wouldn't be looking at injectors at this point)..

What year is the car.. what model?

Please take both of those things and go into Profile.. add them under signature. Then there will never be a question of what year and engine we are talking about.

Thanks

BTW.. did you replace the gasket between the TB and manifold? Sorry..I couldn't remember if I read that.. the post if very long.

As Bill mentions, the TB gasket is a known issue and doesn't love to be reused, so that MAY be part of your problem.