Im running rich, but my pockets are poor.

[pass]

So I have a 84 240 DL and I bought it not too long ago as a first car to kinda fix up a little. Well I noticed the my gas milage is crap, and something isn't right when I start it. When it is cold it won't turn over right away, it takes a few times. Before it is warmed up it sounds like it is about to die the chugs and revs its self up. Well I was thinking it may be the spark plugs so I took them out a turns out that they have a dry, black deposits on them meaning that my engine is running too rich... correct? Could this be my o2 censors fault?