Stock FR, correct psi?

[JimBlackGN]

Before I post on this bulletin, I searched through the forum and don't seem to find an answer that I am looking for, so I had to post this as I know you must have seen this question all of the times. Thanks for your patience.

Bought a fuel pressure gauge and installed in my 87 GN. It has a stock fuel regulator, it reads 25 psi with engine off (cold). When started the engine, it indicates 28 psi. Drove it around for a while and when it warmed up, it increased to approx. 30. Turned it off, it went up to 33-34 psi (engine not running). Is this normal? I have heard many times that I need to take vacuum line off to read the psi. I don't know why it has to be off? Is it mandatory to have it off for an accurate reading? Which vacuum hose do I unplug?

Jim
87 GN w/ 91k miles

 

[equalizer442]

if your running a stock fp regulator even if your fps off theres nothing you can do about it because its non adjustable, btw the line you want to remove is the vacume line that goes to the top of the fpr. most people tune line off but personally im a simple minded person and changeing numbers confuse me so i tune line on and go by my o2 volts on my scanmaster.