So i ended up buying this kit.
https://www.amazon.com/dp/B00VV29NHM...sin_title&th=1
it's got a couple different M8 adapters that fit the fuel rail nipple 'pretty well' i sealed with some teflon tape and it seems to work. no leaks.
Running pressure is 51.5.
Engine off, immediate pressure is 45psi.
Then the pressure starts bleeding off. By morning it was at 5psi.
Apparently that's not normal and chatgpt is telling me it is either the fuel filter and built in regulator, some sort of pump module check valve (pump is brand new and the reason i replaced was because the same issue with the old pump), or it's bleeding off at the injectors (less likely though apparently with no apparent running issues).
it's telling me to clamp the fuel line tonight and check the pressure bleed.
is there rubber fuel line in the engine bay i can clamp that's reachable?
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2005 X5 3.0i - 71k mi (9.2018) -> 81k (9.2019) -> 100k (9.2021) -> 123k (8.2025)
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SOLD : 2003 X5 3.0 - 177k mi (9.2018) -> 186k (9.2019) -> 205k (9.2021)
SOLD : 1997 328is Coupe - Hellrot Red
SOLD : 1988 528e w/ Bullseye s256 / MS2 Extra / GC Coilovers / Yukon Coils ~ 300+ HP