How do you fix a poor paint job over un-primed drywall?

Is the entire wall painted? Finish it with the same paint used and watch for peeling. Drywall painted without primer basically just consumes more paint. Once the drywall is completely painted, allow 3 to 5 days to cure, depending on humidity. Once cured, seal it with a good sealer like Kilz and then apply the desired finish, 2 coats.