Looking at buying a 1993 300 with 2.8. It seems to be in good shape, runs and drives nicely but at idle it fluctuates badly. When doing this there is a little black somke and smells like it is flooding out.

Is there a common problem with this? Can someone suggest what I might be getting into. I'm a pretty decent mechanic and plan on doing the work myself.

Thanks for any help.
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