Just recently bought a 1995 C36 with 98k miles. It ran fine for the first few weeks, and then last week it started acting up. The problem is that, after the car warms up the idle is rough. The idle bounces from 500~1500 rpm constantly in neutral, while in drive it bounces 1000~1500 rpm, while black smoke comes out of the exhaust. Once in a while it dips so low the car dies. This is the first car I bought with my own money, I don't really have the money to bring it to the dealership if I can fix it. I'm trying to single out the problems right now, any help would be appreciated.

BTW, I already changed out the plug, but it didnt fix the problems...


Thanks again!