Mercedes Benz repair: 1985 380sl black soot loss of power, fuel pressure regulator, mercedesshop

Question
hello i purchased a 1985 380 sl with 87000 miles.  a few months after buying car i was looking around engine comp and found a vaccum line disconnected that is connected to a black hose to air cleaner and the other side to what i suspect is fuel press regulator. i hooked up line to its port and now i get low fuel economy, loss of power soot upon start up for about 30 secs and spark plugs are dark and full of soot. is it possible the regulator is bad and thats why line was disconnected? thanks for any info  

Answer
Best guess:
What you describe makes me suspect misrouted vacuum lines.
A failed fuel pressure regulator is possible, but rare.
I suggest you buy the service manual CD..

MB Tech Manuals from MBUSA cost $19.99 plus S&H
http://www.mercedesshop.com/shopforum/showthread.php?t=142445