3.8 stumbling, rough idle after fuel rail change-

Been a mess. Fuel line got damaged... swapped it not once, but twice w/ a junk yard set up. First one was damaged, so I did the second one. I took the car out, and noted that fuel was leaking from the schrader valve. Corrected that, still getting an errant idle with stumbling. I've done the upper intake swap about 7 or 8 times, so I'm faily sure I know all the connections, but list a few that, if missed, would cause this (could be that simple). Any thought on the fuel system? I swapped out the regulator with a newer one, but still a junk yard one. I'm worried about the injectors. Tips are a bit cracked on em, not the best looking units. Give me some ideas here.

Thanx

J