carbon smell on 123 280E

[harvey chupin]

I have a 1980 280E euro and since I bought it a year ago I always smelled heavy carbon and fuel smell when driving with windows down. It started to drive me crazy I think I am going to get rid of the car if I can't fix the problem soon.
The car was running rich when I bought it and fuel mixture and control pressure was adjusted number of times by a mechanic in the past year. Also the valve timing and ignition timing was adjusted.
I took off the air filter and a lot of that smell was coming from under the pressure plate. The vacuum hose from valve cover to the air filter was also all wet inside, I don't know if it's normal. It gives same smell under the oil cap. Inside the pressure plate it's also wet and little greasy and I don't know if that's normal.
I went to Advance auto parts and bought Lucas Oil Stabilizer and it helped the engine run much better but not the smell. I don't know what could it be. Faulty fuel injectors, fuel distributor, warm up regulator?
Any suggestions?

Thanks

[280EZRider]

Assuming the previous mixture adjustments were done correctly - although when we assume, we make an ass out of U and me - I would investigate the federal add-on emission system. Chuck Taylor would know more. Over to you, Chuck................................

[79Mercy]

I think it pretty common. I also have a fuel smell under that plate.