Help! W123 shifting trouble

[Flyin4now]

Ok, I tried to search the forum for help with this problem, but nothing found (yet).

'85 300D having trouble with shifting.

After I press the pedal down to activate kick down, the engine revs and just sits there with no increase of speed and no upshift. If I "mess" with the pedal a bit, it will shift up and start to accelerate. That was the first indication that something was wrong. Now, on top of this, I noticed that at freeway speeds of about 60 mph I can feel the engine hesitating like it's starving for fuel. At this point I cannot accelerate anywhere past 60 mph. If I come upon a climb, the speed just drops.

My first thought, after the hesitation, was that maybe I have a fuel filter or strainer problem. But, if the kick down switch raises the RPM's, I thought maybe not. Even so, why would the trans be shifting (or not) like it is?

Has anyone had something like this happen? I don't know if the shifting and the hestiation are related, or just coincidental. How do you suppose I start to troubleshoot?

I thank you, in advance, for any help in this matter.

Ken