84 turbo car fuel issue
 

Hey y'all I have a 84 turbo that is giving me 50 psi of fuel pressure when I clamp off the return live from the pressure regulator but 0 psi when the return line is not clamped off. I have replaced the regulator and still have the same issue with the new regulator. Getting ready to put a fuel pump in it but I'm not 100% sure thats the problem and I hate just throwing parts at it. Have any of you seen anything like this before?

You may want to test the new ( decades old new reg.) May have a bit of rust inside that jammed it open