E89 Z4 HPFP nightmare

sjobusen

Lurker
Aug 8, 2021
16
0
0
I have the 535 lpfp in my z4 and are monitoring my pressure. When I start my car I have 72 psi pressure, but after a few seconds it drops to 68psi at idle.
At WOT the low pressure is dropping a little more to about 62 psi.
This is with 17t turbos, e30 fuel mix.
Is there a way to raise the lpfp pressure to 72 psi all the time?
 

Neg89

Specialist
Jul 4, 2021
58
5
0
I have the 535 lpfp in my z4 and are monitoring my pressure. When I start my car I have 72 psi pressure, but after a few seconds it drops to 68psi at idle.
At WOT the low pressure is dropping a little more to about 62 psi.
This is with 17t turbos, e30 fuel mix.
Is there a way to raise the lpfp pressure to 72 psi all the time?
I am just thiking of my problem right now. I want to run pump fuel only on my pure stage2 cast. How do you monitor LPFP on Z4. I just bought fuel line and sensor from 335.
I have the 535 lpfp in my z4 and are monitoring my pressure. When I start my car I have 72 psi pressure, but after a few seconds it drops to 68psi at idle.
At WOT the low pressure is dropping a little more to about 62 psi.
This is with 17t turbos, e30 fuel mix.
Is there a way to raise the lpfp pressure to 72 psi all the time?
 

sjobusen

Lurker
Aug 8, 2021
16
0
0
I am just thiking of my problem right now. I want to run pump fuel only on my pure stage2 cast. How do you monitor LPFP on Z4. I just bought fuel line and sensor from 335.
I just added a old style pressure gauge with a hose into the 335 fuel line... instead of the oem sensor. Just putting the gauge at the windscreen on my wiper when I want to look at it.
 

Neg89

Specialist
Jul 4, 2021
58
5
0
O.I understand.IS there known e89 with added LPFP sensor that can be logged thru mhd or at least observed real time.
 

Neg89

Specialist
Jul 4, 2021
58
5
0
Hello. So i upgraded to pure stg2.cast turbos. waiting to get Wagner evo3comp Fmic. Tuner says this
"" normaly railpressure is no problem up to ~550-600hp if hpfp is in good condition and lpfp is upgraded.""


so i am confused ,New LPFP535pump, new hpfp,new regulator/filter, different ekpm3 =no difference in HPFP drops at midrange. Is there any gremlin,electeronic issue.?

Bau the way,do someone make the lpfp running with PROTOOLS, to epty tank. I was doing so,presure was barely better than running on plain grawity .
 

Neg89

Specialist
Jul 4, 2021
58
5
0
Hi. Does someone tapped in the e89 long fuel line. I want to put in check valve but read somewhere that e89 have bigger diameter fuel line. To be clear i even dont know the inside diameter and what fittings to use to convert from AN type to fuel line..
 

Neg89

Specialist
Jul 4, 2021
58
5
0
Also I have special question for you e89 guys if you prime the low pressure fuel pump using Pro Tools or similar software what pressure do you see coming out of low pressure fuel line as I mentioned it before the pressure which I observe it was nothing more than Maybe few PSI it was looking more than just gravity flow I Believe if it was 60 or 70 PSI the fuel will come out of tank with much greater force .
 

Krampus

Private
Aug 8, 2020
40
21
0
Finland
Hi. Does someone tapped in the e89 long fuel line. I want to put in check valve but read somewhere that e89 have bigger diameter fuel line. To be clear i even dont know the inside diameter and what fittings to use to convert from AN type to fuel line..
Use AN6 fittings.