1995 Lincoln Continental shutting down at RPM

I just bought a 1995 lincoln cont. 53,642 miles great shape, old man owned it, today I was merging into traffic and hit the gas when I did that it started jumping and hesitating rpm's dropped to 1 and when I would hit the gas it would do nothing, if I feather the gas it kinda stalls then takes off and jumps some more, then started shutting off, so I was having to start it and throw into drive before it stalled out again, after finally getting onto the main road it was ok didnt stall anymore drove in the neighborhood and nothing abnormal, seems only happens when I hit the gas and rmp's go over 4000. Please help thanks.