Thanks sixto for your coments on this issue.
Seems that I have to talk to the lokal MB shop again and try to make them find the right diagram this time. Hopefully a wiring diagram will solve my problem, othervise I will get back with the technical side of the problem.
To coment on youre problem ejsharp, I can just say that my MB is probably stoping since it's running rich, and I think it's because the engine controle unit gets a faulty signal from the inlet air sensor. Saying it's -25 degC instead of +20degC. The sensor is ok and so is the ground wire, but to wich pin does the signal wire go??? This is where the need for a wiring diagram comes in. I don't like the idea of cuting up the hole wiring harness to follow the wire. Somewhere it's probably getting in kontact with someting else and creating a faulty signal.