88 grand am: having problems while running

So, don't know where to start with this one, but heres a general break down of what is going on, every now and then when i stop the car will just die, its starts right back up with no problems but it just dies sometimes when i sit and idle, also when i am running right around 35 mph or so it sometimes starts to jerk a bit, kinda sounds like its having problems pushing the fuel through, it revs up and down until i press on the breaks and drop below 30 mph, then it stops doing it. And finally this problem started a few days ago, but it is having a real hard time shifting up, i will get up to almost 40 mph and 6000 rpms before it will even slip into second gear, or if i'm on the highway and doing about 60 and press the gas to accelerate, the rpm's jump but i do not accelerate at all really. I have replaced the throttle postioning sensor and put a new fuel filter on it, but if anyone can give me an idea of what is going on with this car i'd would greatly appreciate it

What did you find out about your car? We recently purchased an 88 Grand Am as a second vehicle, and it's doing the same thing yours is. It dies while idling, won't accelerate at all, and won't shift up without hitting the brake. I'd love to hear what you know.

Thanks,
Amanda