Drivability problem

[Steve Rosen <carsrme@li.net>]

My temporary 85 cpe began hesitating when cold for the last few days but
drove fine when warmed up.( cold start valve and full throttle switch
haven't been working before this anyway) 

This morning it didn't clear up. It got worse. Barely able to accelerate
from idle.
Did manage to get to work. Black smoke exititing the tailpipe all the way. 

All the plugs are equally black. No vacuum leaks that I can find, all the
grounds are good. 
It runs a little better if I put some weight on the fuel distributer
adjusting screw.

What could cause the car to go so rich. Cat, ecu, etc???

TIA

Steve