1995 Chevrolet Camaro rough idle/sporadic/stalling/rich

The car is hard to crank. Hits hard like gonna break starter. When cranks idles at 1000 rpms till temp is between 160-180 then the idle is fluctuating roughly (like it has a cam on it)between 500 & 1000. There is constantly an output of white/blue/gray smoke from both tail pipes that has very rich smell. After about 5-10 minutes of all this the car will stall and will not crank for hours. Put gm scanner on it and the car had only one code stating to check the 02 sensor. That has been replaced but still no change and no other codes. Ran all wires and hoses and found none to be worn, loose or corroded.