Last week I finally had enough of this and sent the Benz to a highly recommended shop that almost exclusively is reparing Mercedes-Benz'es.
It took the mech almost 4 working days to come up with the conclusion that he couldn't pinpoint the exact problem..
What he DID find was several corroded electrical connections at various relays and at the ignition coil. And one of the pins on the relay that says "Kickdwn..something" on it, was corroded entirely away! -This took care of the hesitation-from-standstill problem, but fuel was still pouring through.
Finally he replaced the ENTIRE injection system with a used one from a wrecked 300E.
He also replaced the cat, since it was shot after having been soaked in unburned fuel for so long.
Now he could adjust the mixture to spec.
I was there when he made the final adjustmens and i was happy as can be. Finally my Benz were running smooth again. -Or so i thought..
Yesterday morning i went to start the car. (first cold start since repair). It started fine -and immediately died.
This repeated a couple of times until it barely kept itself running with a very rough idle at 500 rpm. -Also after warming up.
The car runs perfect now exept for this rough idle and an occasional stall after breaking to a standstill. And gas milage has improved drastically
But we're going to the shop again..
This is going to be REALLY expensive i'm afraid..