1998 Ford Crown Victoria

I'm not the best at articulating stuff, but here is my problem. When I hit the gas pedal my car jerks, if I floor the pedal it will usually take off like a bullet or if I barely touch the gas it will usually accelerate smoothly, but if I give the car too much gas it want to jerk. I was thinking it was the torque converter because if I'm in neutral or park the engine revs up fine without stumbling and if I go from park to reverse or from park to drive the transmission grabs quick and strong. What do you guys think the problem could be? No check engine light on either.

Thanks,
Chris.
:)