1988 town car stalls after startimg in park. Or putting in gear

Ddear eric i really need some help man. Im working on a 1988 town car with a 5.0 and a AOD trans. The car runs fine in neutral quick throttle responce and everything but in park it will start up then shut off within 1-2 seconds and stall instantly when you put it in gear. I had a donor car that i tried switching parts with that ran good. I tried the map sensor,pcm,iac,throttle position sensor, and even the torque converter. Ive been a tech for 10 years and have never seen a trans stop a car from running and neither have the guys i work with. Im out of ideas please help.