1994 eagle vision transmission problems

I bought a 1994 Eagle Vision ESI 3.3 liter EGA V6 with a 4 speed 42LE automatic transmission 2 week's ago. Until 2 week's ago it had not been driven in 7 years only the engine started. After I purchased it I drove 267 miles back to my home in it with no problems. While driving it to town last week it quit shifting all together and made a whining sound. I pulled over, put it in park and killed the engine, then checked the fluid level which read full on the dip stick but it was a brownish color. After 5 mins I restarted the engine and when it shifted from 1 to 2 gear it stuck in 2. I drove to Wal-Mart bought transmission slip stop by Lucas oil and added it. It shifted correctly and stopped whining for about 5 miles then after stopping at a stop light it would not shift out of 2nd gear again. I parked it at home for a week and today I changed the transmission fluid and filter. I cleaned all the sludge(Yes black sludge)out of the transmission pan and there were NO metal shavings on the magnet. I used STP ATF+4 as that is what it calls for, and it shifted great for about 35 miles then it dropped out of 4th and stayed in 3rd gear. I stopped at a red light and it would not shift back into gear and made a kind of grinding type noise. I put it in neutral, rolled it into a gas station and checked the fluid again which read full and was still nice and clean and red on the dipstick. After letting it idle in park a few minutes I shifted into reverse but it would not go into reverse it made the same horrible noise. I put it in park then into drive and it started to go but began that noise again and quit "driving" the car forward so I put it in neutral and it continued the noise and acted as if it was still trying to engage in gear. I put it back into park, killed the engine and called a friend who pulled me home, with engine not running and the transmission in neutral. After an hour I went out and started the car, moved the shifter to reverse but it won't go into reverse and no longer made any noise. I placed the shifter into drive and it engaged with no noise. I'm need help as for what I can do to fix this. Is it a pcv valve sticking or the TCM and PCM or what?

 

I have a 94 Eagle Vision esi 3.3L V6. Some time ago the transmission slammed into second gear as I was driving.
The Dealer put a new selenoid in the transmission and all was good for a year and a half. Then it begin to drop out of gear as I was driving and once coasting down to 35 mph it would slam back into second gear. No noises or anything. I would pull over and cut the engine and wait a few minutes. After restarting I could tell by the way the gear selector engaged by the feel of it whether it would run or remain sitting. I'd go thru this a few times and then it would eventually resume operation. it may run a few miles for for the rest of the day before it did it again.

Since I've owned it the main issue I have had was replacing the fuel pump, replacing the key switching device as the points had burnt out that operated the electric fuel pump, (I had made a jumper wire from one side of the fuse
to the fuel pump that went to the battery....this had a fuse in it and a rocker switch so I could hot wire the fuel pump and start the engine. This proved the ignition key system had to be replaced) Once done the car would start and run with the key again. I've replaced the oxygen sensors, crank & cam sensors, both transmission sensors
(on the left side of the transmission)

I had had a Dodge Lancer in the past and it seemed to eat those throttle position sensors and after replacing the fifth one I sold the Lancer. This Eagle has the original throttle position sensor.

Has anyone else had this problem with the transmission just quietly slipping out of gear. I'm wondering if the throttle position sensor is worn to such a point where at 55 mph or so that it's signal doesn't get to the computer somehow?
And this may have some bearing on this problem.

The car runs great and is a pleasure to drive when it runs right. And it still looks great and that's why I'm trying to restore it.