Need Help! 1990 MarkVII LSC

I have a mint 1990 LSC with 70,000klm....but.....after a ride and I put it in park it stalls or the motor surges until it does stall. It will start again right away and idle fine. I can put it in all gears and back into park and it is fine. The only time this occurs is when I put it in park after driving it.

Thanks guys. Got it solved