okidoc

I know this is kinda a strange question. Does the fuel pressure reg on the driver side fuel rail on the 3.0 hold vacuum. Meaning if you draw vacuum on it, it should hold the vacuum, right?

Mine seems to have gotten louder(I could just be neurotic). I attached a vacuum pump to it and it didn't hold any vacuum. So how's bout it?

nunsa

The FPR will measure vacuum or pressure, depending on throttle opening, The fuel psi w/ vac attached should be 33 - 37 and over all psi, fuel pressure should be 38 - 44 @ the cyl's, ahh! If I remember right!
The job of the FPR is to keep the fuel pressure constant and return to the tank? I'm pretty sure, if I remember! :pat:

Are you sure it's the FPR that's getting louder and not a vac leak somewhere?
Good Luck!
Harry

okidoc

but it should hold a vacuum. If I put X amount of vacuum I should come back in ten minutes and have X amount of vacuum still, correct?

superjoe83

yes it should, i would check your vacuum pump by plugging the end of the line that your are attaching to the regulator and see if it holds vacuum by itself

Unhappy99

Yes, it should hold vaccuum. Ten minutes might be asking a bit much, but if it does leak, it should be quite slow.

p.s. More vaccuum (say 20mmHg) yields lower fuel pressure. Less vaccuum (say 0mmHg) yields higher fuel pressure. Putting this another way, idle (closed throttle) has high manifold vaccuum and lower fuel pressure. WOT has low manifold vaccuum and higher fuel pressure.