94 passport fuel pressure regulator question

I have a 1994 Passport 3.2 171,000 miles.
The question I want to ask is what should happen when I pull the vacuum line off the regulator? I am having a problem with the truck not taking the gas off idle, idle is great(See post Passport Runs Lean.) I had the truck running today (idle) and I took the vacuum line off the regulator and tried "revving it up" but no good, still won't take the gas, just boggs down. I would think it would affect the fuel pressure somehow by taking the vacuum away but the revs stay the same no matter if the line is on or off [line plugged with bolt]. I checked the vacuum and was getting approx. 50# vacuum (In the green area of the vacuum gauge.)at the hose coming from the manifold to the regulator.
{No gas or vapor in the vacuum line}

Thanks for any help here.
Bob K.