N54 LPFP Q

N54E92

Lurker
Aug 17, 2020
10
0
0
Hello,
I am about to get a custom tune for E85 (thinking just a smaller E25-E30 blend). Is my lpfp keeping up enough for it and looking healthy in this 3rd gear log?
Thanks a lot!!

 

GreyNBlueE92

Sergeant
Oct 3, 2018
266
93
0
28
OH
Ride
2007 E92 335i
Looks fine for whatever youve got in there

You can also diy a 450 for about $150 if you're handy
 

N54E92

Lurker
Aug 17, 2020
10
0
0
That’s still full pump gas, sooo it’s a little on low health correct?
How does my high side look? Could a leaky injector cause low rail pressure or would it only be bc of hpfp?
 

GreyNBlueE92

Sergeant
Oct 3, 2018
266
93
0
28
OH
Ride
2007 E92 335i
Low side looks decent, but stock i hear people dont run more than e20 or e30 idk myself. I upgraded my pump as soon as I started messing with ethanol.

Could be a weak hpfp, the pressure definitely looks kinda low for pump gas and that low of boost.
 

N54E92

Lurker
Aug 17, 2020
10
0
0
ok thanks a lot! So you would start with the high pressure fuel pump then? Would my fuel pump control module have anything to do with it/any other reasons for low rail pressure?
 

GreyNBlueE92

Sergeant
Oct 3, 2018
266
93
0
28
OH
Ride
2007 E92 335i
Your fuel pump control module (EKP) controls the lpfp. The hpfp is spun mechanically and the dme controls a valve on the hpfp (VCV) to get the volume/pressure it needs.

Id get a couple logs with a few gallons of E on say a half tank, if the trims are high +-20, add more 93. Id replace whatever drops pressure first. I like my hpfp above 1500 others let it run down to 1200. Lpfp should stay above 60 for the most part
 

N54E92

Lurker
Aug 17, 2020
10
0
0
sorry for the delayed response... but thanks a lot! Should I just go ahead and build my own walbro 450? Will that boost up my rail pressure a bit as well?