black smoke runs rough and no power

please help me out, my sons lincoln was having a problem where it would loose power but still go. now it will start up right away but runs rough and blows black smoke, no rotten egg smell, but no push power.(it wont go.)

What year?

it is a 1990 8cyl

it is a 1990 8cyl


Hmmm, 1990...
That's the big 5.0 litre correct?

There's a bunch of 5.0 guys over here:
http://www.lincolnsonline.com/cgi-bin/ultimatebb.cgi?ubb=forum&f=24

I'm not too sure what makes the 5.0 tick, sorry.

Hope this helps :)