It takes me awhile to find them when I need, but there are at least several really good active threads on troubleshooting and adjusting the transmission. Subscribed to this one - it's a long read but there is a lot of good information. Post vacuum/transmission questions there and you'll get some good help.
It's CRITICAL... how you set your transmission's vacuum system on your diesel MBZ...
There's another one on adjusting the modulator and another on adjusting the Bowden cable. Do these yourself before you take it to a professional that won't have the patience that's needed. These are all simple DIY tasks and could very well fix all your problems. If not, search for the K-1 kit fix.