problem when stopped at a light (periodic)

[tmoney5500]

I have a 98 Gst who just had its tranny rebuilt two years ago. I am having this periodic problem where I would be at a light or turning off of a street and the car will lose most power when trying to accelerate. It will move slowly at low rpms and then rev like its in neutral when the gas is depressed a little more. Then the car I turn off the car or stop at a gas station to check my fluid and when I leave/start the car will run fine with no problems. I checked the fluid and its fine and not burnt. I do not shift it like a manual and It is only a problem some of the time. I was first thinking the stall converter went, then I read about the tps and how it might be causing this. There are no other symptoms to report. All of the other gears work fine and shifts are smooth. I am unsure as to the cause of my problem. There is no check engine light or pending codes as well.