Ok, your are correct. That makes NO sense. Hmmm.
I would fix the pressure to the regulator first. I would get the pump off the car and look very close at that internal bypass valve and make sure it’s not boogered up and stuck half open or something. And if it’s working, get the high pressure spring for it. I used to have a test fixture to test little springs like that for when I ran and was tuning mechanical fuel injection all the time. I think I sold it though.
You need to get that pressure up to to at least 15 pounds. 20 would be better.
Once you get that corrected you can tackle the pressure after the regulator.
4 pounds of line pressure to the regulator is way, way too low. That has to go up first.
That’s crazy…
