Today, I opened up the regulator (115 psi) and cut it back at the sander. It was much better. I didn't have time to do much. I'll get back to it this weekend, I hope.
I already told you. Stop screwing with the sander. Bypass the regulator get ahead (towards the compressor from any trap or regulator. Take a nozzle of some sort and confirm you have lots of air. Then hook up the sander and see what you get.
Might be a regulator defective.....How cold is it? Might be some moisture in there freezing