no acceleration after stop

after being at a stoplight for a little while, my 94 grand prix doesn't accelerate. when you push the gas pedal, it does nothing, just goes at a speed that seems even slower than idle. it acts like it's in neutral except the engine doesn't rev. after about 10-15 seconds, it kicks in and the car takes off. this is a pretty dangerous problem considering it's left me basically stranted in the middle of a turn in a busy intersecion. Anyone have any idea what the problem might be? thanks

Sounds like a problem with the throttle position sensor (TPS).

Thank you for the suggestion, I will replace the TPS and see if the problem persists.
It was also suggested to me that the problem might be with the fuel filter. Someone also suggested that the brake might stick after being pushed down for a considerable amount of time. The TPS seems to make the most sense, but what do you think of those other suggestions? Could they also be part of the problem?
Thanks

I would have to go with carnutcass and say it might be the tps, post when you find what the problem was

i'll post when the problem goes away, but it'll take a while to figure out because it doesn't happen *all* the time, so it will take a while to figure out if it's gone for good.i'll give it a week and see.

I have another question.. i just replaced the battery terminals because they were bad. the next time i drove it after that, the speedometer needle went crazy... just kept spontaneously going from left to right basically. Could this be because of a problem with the terminals..maybe not connected tight enough... or... something else maybe?

Thank you for the suggestion, I will replace the TPS and see if the problem persists.
It was also suggested to me that the problem might be with the fuel filter. Someone also suggested that the brake might stick after being pushed down for a considerable amount of time. The TPS seems to make the most sense, but what do you think of those other suggestions? Could they also be part of the problem?
Thanks

Wait about just going out and buying a part. Let's make sure that's the problem. No sense pissing your money away.......sorry, that's the dad in me talking.

I suggested the TPS as a possible because I had a similar problem on my Porsche. I'd say that it's probably not the filter because the problem would most likely be more frequent than what you're experiencing. Also, fuel filter related problems can happen throughout the RPM range. I've seen it affect only the higher revs but I've personally never seen a filter related problem that went away after you accelerated.

I'd also say no to sticking brakes due to the fact that your RPMs don't go up when you depress the accelerator. If the brake(s) were sticking your car would feel like you were brake torqueing....know what I mean?

If you want to, PM me with your e-mail address. I'll copy the diagnostic procedure from my GM Service Manual disks. It's too long to post here.

when i took the battery out to change the terminals, i found a thin tube under the battery that was cut. my dad said it was a vacuum tube. we already mended it, but could that have had anything to do with the problem? if not, what other potential problems could it have caused?

& just fyi- the speedometer problem i mentioned was infact related to terminals not connected properly (fixed now).

Yea, you're right, I guess I'll wait on replacing the TPS until I'm sure. I have a repair manual and i came across a page where it shows how to test the TPS with a voltmeter. would that testing tell me if it's the problem, or is that a different kind of testing?
Thanks to all for helping :)

update-

fuel filter replaced
battery terminals replaced
broken vacuum line mended
tested the tps with voltmeter, tested fine.

since those things were done, the problem hasn't recurred. Hopefully hopefully *hopefully* I guess that means it might be gone.

could the problem have been caused by the vacuum line that was cut? what do you think?