I have a 95 F350 with 5.8 that sometimes runs great then other times it starts and runs very rich to the point that it's not driveable, spits, sputters, black smoke pouring out the pipes. The fuel pressure regulator was changed, the map sensor was changed. What else should I try? Thanks

 

One thing you might consider,
Get hold of a fuel pressure gauge, connect it to the schrader valve on the fuel rail and watch what is happening with the fuel pressure. That way you will be sure the fuel pump is not pushing excessive pressure and also that the pressure regulator is operating correctly. Fuel pressure should be 35-45 psi.