Thanks Steve. Good short answer.
I have just finished changing my transimission fluid and filter that I did immediately after posting this question. The car seems to be shifting about 80% better. I guess my modulator will need adjustment and may have to take it to a shop or the dealer. It is hard to get to or maybe there's a trick to get to it. I have a new updated one in case the old one is leaking. I suspect I have a vacuum leak in the modulator. The vacuum line going to it is not leaking. I used a vacuum pump and it held vacuum alright.
1993 190E 2.6
Advanced Diesel Systems Test and Research Engineer