fuel pressure vs boost and so on...

[86GN-862+2]

I hope I am NOT asking a stupid question here. Just need to clarify this for my own benefit. :redface:
Being how I got a vacuum/boost gauge and a fuel pressure gauge, how would I figure the fuel pressure vs boost relationship? I think I read that for every lb. of boost one must get a lb. of fuel. When do I start to account for fuel...after the gauge reaches "0" or as soon as gas pedal is depressed? I ask this because my car, for example, pulls over 15#'s of vacuum at times while it idles and even higher when engine is revving down to normal. Hope I made sense here. Fuel pressure does rise as needle on boost gauge moves to 0 then boost side. The 237 fpr I installed is a bit out of whack possibly because it reads around 43#'s hose hooked up and around 46-47#'s hose unhooked or maybe it's the fuel pressure gauge that's messed up? BL's are 117-119 while cruising and around 124 while idling and WOT. Also, is it possible for INT to go in the same direction as BL?? I thought INT always went the opposite way from BL. Thanks in advance.

 

[mikestertwo]

You should have 1# of fuel pressure for every pound of boost. So if your base pressure (line off the regulator) is 42# then you just add your boost pressure (above "0" on the gage) to your base pressure. In this case 42+boost=fuel pressure I would verify your pressure with another gage. Yours may be bad.

 

[86GN-862+2]

You should have 1# of fuel pressure for every pound of boost. So if your base pressure (line off the regulator) is 42# then you just add your boost pressure (above "0" on the gage) to your base pressure. In this case 42+boost=fuel pressure I would verify your pressure with another gage. Yours may be bad.

Thanks for the clarification. I am going to check fuel pressure with a mechanical gauge in place of the electric sending unit I got in it right now.