Fuel pressure regulator info?

Not sure if I have a defective redline fuel pressure regulator? How do you set the pressure? Plug the outlet and adjust or at higher rpm or idle? I thought I had this thing dialed in for my Weber 38 but returned from a shakedown run and the pressure was reading way low, maybe 1.5 psi. The car ran great but the pressure reading seemed unresponsive when adjusting the screw in and out. I rubber mounted this regulator and have a liquid filled gauge on it. Any tips? Oh yea, the fuel pump is a 'new' OEM style mechanical.

Just thinking out loud ,
You could try closing the regulator down ( tighten the adjustment screw)and see if it closes off the fuel ?
Or do the old "Pump fuel into a container"trick, see if the regulator adjustments make a difference ? Go way tight, then try way loose ?
DannyG

would U lower pressure w/a loosen of the nut, raise w/a tighten?
What's the target FP for the "36"?

Run the vehicle, pinch the vac line, C if it changes the reading.
Run vehicle, pinch, adjust to target FP, remove the pinchers, look at resultant reading.
It shouldn't change...

I may have the regulator pressure directions mixed up, good point !

Thanks for the responses guys! At times I move the adjustment screw in and out and there is no change in the very low reading on the gauge. New gauge but could be wrong? I doubt if the mechanical pump has variation in its output after it warms up, but last night I fired it up and the pressure was where it ought to be. One way to fix it - Stop Looking At It!!