Brand new HPFP taking a dive, while LPFP seems strong.

[alvinhobh]

Replaced all possible mechanical componets but still struggling with fuel! Please help!

Car info:
2007 335i 6MT
RB next gen plus turbos
FBO- the usual
Fuel-it stage 3 LPFP
Fuel-it PI 550 injectors
AIC2
FPS in-line filter/FPR with return line

To try to chase this issue, I went away from my custom tune ( since still in progress), disconnected my PI controller, removed my FF motiv kit, and uploaded an MHD OTS tune with e50 in the tank.

Two issues I see

1) Even with only e50, targeting not even 20psi, the HPFP is crashing badly
2) Bank 2 lamdba is showing symtoms of leaking injectors- even with new injectors...

Parts replaced (All OE from FCPEuro)
HPFP - Replaced twice!
HPFP sensor
Index 6 injectors - Bank 2 look like was leaking, still looks the same after replacement
All new oxygen sensors - OEM Bosh
Upgraded to MSD81

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[droscoe]

I had the same problem with the fuel-it stage 3 lpfp, because it utilizes an OEM primary pump (re-read the fuel-it description of the lpfp closely) and the E85 tears it down then sends the primary pump internals through your fuel system. The secondary pump will give you false lpfp pressures under short loads; as it did me.

Your LPFP, HPFP and all of your injectors are most likely going to need to be replaced; as mine were. Even the PI ones.

I had to ultimately replace all of it and went with a stage 3.5 from Precison Raceworks, all new fuel lines from tank to HPFP and a FX-180 HPFP with inline filter from Spool. Not to mention two sets of injectors.

I have the invoices to support it, if need be.

 

[NoGuru]

You have just about the same setup as me. I took off the PI rail and pulled the filter inside the HPFP put it all back together and pressure is back where is should be.

 

[iminhell1]

So where exactly is the problem here?

HPFP is fine under load far as I see.

3rd gear your're having throttle closure after 4,000 RPM (full boost), because you're overboosting. Which should be expected running a bigger turbo and a map meant for stock turbos.

Not sure what you think you're seeing, but I don't see it. And I'm not sure why you're taking steps backwards when none of that will help with the custom tune you where working on (and do need).

 

[NoGuru]

So where exactly is the problem here?

HPFP is fine under load far as I see.

3rd gear your're having throttle closure after 4,000 RPM (full boost), because you're overboosting. Which should be expected running a bigger turbo and a map meant for stock turbos.

Not sure what you think you're seeing, but I don't see it. And I'm not sure why you're taking steps backwards when none of that will help with the custom tune you where working on (and do need).

I'm not sure what you are looking at but his HPFP is tanking bad. Anything under 1500 is not good and at some point he is below 1000

 

[iminhell1]

I'm not sure what you are looking at but his HPFP is tanking bad. Anything under 1500 is not good and at some point he is below 1000

You need to look at load ....

 

[NoGuru]

You need to look at load ....

Ahh I see it now, thanks.