Sound like you have a oil feed going into the intake, I don't know what engine you have but any oil is raw fuel if put thru the engine intake, crankcase vent system gone haywire, a blown set of rings pressurizing the crankcase, somehow if it is smoking hard you are getting either raw fuel or oil into the combustion system. Did you change the fuel Injection pump or the transfer pump?, big difference between the two.
How much oil in the crankcase? Does it smell of fuel?