why does my car do this? on 1992 Plymouth Grand Voyager

As I'm driving my car I'll come to a complete stop then I'll push in the gas the car will go a few feet and start coasting with my foot on the gas. Then I have to press and unpress the gas several times to get the car to go foward. Once I get past the thirty mile an hour mark the car does fine but every time i come to a complete stop and then try to speed up i have to do this little routine.

Do the engine RPM go up when the "coasting" problem occurs on your 1992 Grand Voyager? If so your transmission is probably slipping. Working the throttle will allow you to gather enough speed for the transmission to shift into the next gear. Road testing your van with a qualified technician would be the best way to confirm this.
No the RPM doesn't rev. The needle on the spedometer and the rpm drops completely.
1 more answer
Throttle position sensor or some such? Any MIL codes stored?