Put a fuel pressure gauge on it and let it sit for a while and see if it bleeds down. I believe it should be right around 45 psi while running and when you shut it off it shouldn't bleed the pressure down much more than that. I know those "poppet" style injectors were horrible for gunking up and being stuck open. Also, what fuel pressure regulator did you get. I went through 4 GM ones on a Bravada one time before I finally got one that didn't set a check engine light.

 

I got a Borg Warner fuel pressure regualor. It seemed to hold, and the car did in fact run better after the repair, just still not properly. Car might need too much (radiator, 2 window regulators, HVAC fan doesn't work on highest speed setting, driver's door lock switch doesn't work) to be worth spending too much more time on this. I messed knocked around the PCM, and it seemed to work fine for a little bit, but that could also be coincidence since it went back.