91 Mercedes 560 SEL Low Compression & Shaking...

[nissandotson]

Can someone please "Help" me with figuring out what is wrong with my car?

I have a 91 560 SEL w/153K miles on it ,that is in otherwise good condition. Except that since February, the car has a constant skip/shake especially when stopped. I had a tune up done in March and all spark plugs and the distributer cap was changed (the spark plug wires were not changed). However, the problem still continued. I kept taken it back to the shop, but to no avail. They thought it might be calibration, but did not know. I even paid for diagnostics from 2 different shops, still noting.

Finally, I was told the problem was the intake gasket manifold by the 3rd shop. I took the car in on 11/18 to have repaired and the shop broke everything down, but never completed the repair. It turned out to be a nightmare! I ended up having my vehicle towed to another Mercedes shop last Tuesday and that is where it is currently. They have put everything back together. However, they now say that there is low compression and the car still skipping. Might be the fuel injectors. They are still working hard to repair. In addition , the fuel gauge does not work. The car appears to have a full tank of gas and than runs out all in the same day. What do I do to have these problems rectified, without it continuing to cost me a small fortune? So far it is costing me $1600-$2000 for the current shop alone.
I would appreciate any help and/or suggestions.