The car isn’t misfiring or breaking up but i’m like 95% sure it should be higher even at idle. In one of the logs it did touch 55-57 psi during WOT and i feel like it’s causing the hpfp to work harder. I threw out the original one like a dummy man …
LPFP Psi Too low?
- Thread starter Bimmerny
- Start date
It may not be at the perfect factory specificed pressure but im sure even they have a range listed. As long as your low pressure is oscillating and not just taking a steep dive and staying low your ok. And obviously if your hpfp isn't crashing you've got enough fuel. The low pressure sensor on the n54 is in a difficult spot. Speculation says that because the low pressure sensor is so close to the pump that the vibration from everything and demand and pull changes from the hpfp cause it to oscillate that way. It really needs a pulsation dampener or to be relocated to smooth it out. Even with all of my work done i still have oscillations but, they are greatly reduced. The injectors also add to the oscillations from their own pulsing and being right next to the cylinders will add to it. From an engineering standpoint, it is accurate. It gives an unfiltered raw image of what's happening to the fuel at the pump. I wish we had a log on a completely stock car just for baseline comparison.
so the bucketed DIY needs a T fitting ; one side to the venturi and the other to the fuel line to the HPFP.
The T fitting and the 90° fitting got the same connection and can be connected to the n54 fuel line. When my venturi line poped out, Ive removed the T and plug the 90° directly to the n54 fuel line.
now im back to the T fitting so I can run low fuel level, and randomly this morning I was at 72psi even with the venturi....
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Thanks a bunch, i may have to replicate this since i’m also bucketed. Looks very clean and seems to work well if you are hitting 72 psi
last picture not mine, but 2 first yes. I dont have clear pictures.
For now it works, and I can daily the car.
From my last hose faillure, Ive attached it with ziptie around the venturi a little bit like this DIY + a hose clamp : https://www.1addicts.com/forums/showthread.php?p=22273254
