aftermarket fuel pressure regulator

Jahskew22 · Post by **Jahskew22** » 30 May 2024, 11:30

1998 v70xc

OEM fuel pressure regulator went out, so i decided to upgrade to an adjustable aeromotive fpr and -6 ptfe stainless braided/hardline (for supply behind engine) wrapped in a titanium fiberglass heat shield. Has anyone fitted one of these into a whiteblock? I have "customized" the fuel rail to allow the fpr to be after the fuel rail instead of down behind the axle. I have it all plumbed and heat shielded, but i am having trouble adjusting the fuel pressure on the unit. There is no change in pressure if the adjustment screw is screwed down to maximum or backed out all the way. The pressure stays constant. Starts right up, and sounds good, no smoke, and pressure increases when i rev it. Drives fine but i havent pushed it. i have about 50 miles on this afpr project, 0 highway and i was getting 22mpg (which makes me think the fpr has been declining for a while bc i have had this car for 3-4 years and never got about 17mpg). i was reading another forum where they had a similar problem but they had their return/supply hoses mixed up. Funny thing about that is i have already made that mistake, and my fpr read 0psi, so i "know"(i dont know sh*t) thats not it. also when that happened i had mistakenly plumbed the fpr upstream from the fuel rail, like the stock fpr.

My hypothesis is that the ecu is constantly correcting the fuel pressure, compensating for the mechanical changes when i turn the adjustment screw.

Question
How do i test this hypothesis? or did i infact mix up the return and supply lines, and if i did is there an easy way to test that without dumping fuel everywhere?

thanks in advance, cant wait to get this beast back on the road!!

Post by **Sveedy** » 30 May 2024, 12:52

Ok, but why ?

Jahskew22 · Post by **Jahskew22** » 30 May 2024, 14:33

psh like id give away my evil plan so easily your gonna have to take me to dinner first

Post by **Sveedy** » 30 May 2024, 16:00

You're a bit south of me.

Jahskew22 · Post by **Jahskew22** » 30 May 2024, 16:02

any idea about my fpr problem? ill drive to you lol

Post by **Sveedy** » 30 May 2024, 17:07

I'm afraid not at all. I am running a different fuel pump, wiring for it, and injectors, but still the original FPR.
I'm guessing that the tune is link which makes it all work. But you might try over at S.S. and see if someone over there has done what you're doing. Worth a try....

Jahskew22 · Post by **Jahskew22** » 30 May 2024, 17:24

whats ss? i just saw the aftermarket forums, is that what you mean?

Jahskew22 · Post by **Jahskew22** » 30 May 2024, 17:38

Post by **Sveedy** » 30 May 2024, 18:31

Hey now, no politics. Only the flag option which is fine( though it would be nice to opt out of that as well ). It can lead to a minefield, and the folks who run this place don't want it blowing up

.
Think of it as a Volvo Garden of Eden. Oops, I might have just stepped on something.

S.S. is Swedespeed com. They are more focused on performance etc....

Jahskew22 · Post by **Jahskew22** » 30 May 2024, 20:17

dang autocorrect lol thanks homie