Losing fuel pressure and my sanity :(

JohnDaviz

Sergeant
Jan 6, 2019
355
201
0
Ride
335i E92 DCT
So besides the rail pressure.

Looking t your posted log makes me raise my eyebrows.

As soon as your log starts you get this:
1606910291875.png


Your Lambda AFR Bank 1 is rich af although STFT1 is pulling max fuel (-34%).
There is something going on on your Bank 1 which may correlate with defective injectors. There may be one or more stuck open.

OR your tune is fu**ed up badly.
 

RuskiRacer

Sergeant
Jul 17, 2019
429
157
0
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2009 e93 335i
If you have a catch can on the car you should be able to tell if the injectors are leaky. It should have some fuel in there.
 

TheFixer

Corporal
Aug 16, 2020
240
127
0
Tennessee
Ride
2008 535i, my wife
I just started getting a slight smell of fuel on cold starts. I should probably check the filter. Where is the fuel filter located? Is it under the car after the fuel regulator? Thanks.
Under the rear seat, drivers side..... on a 535i. Think it is the same for you.
 

JuniorB

Sergeant
May 9, 2017
343
111
0
Rhode Island
Ride
07 e60
Since you done eveything from the pump back, shtart looking from the pump foward. Check the adapter off the vac pump, the gear itself, sprocket, and chain. If at high revs, there is slippage. That pump is all mechanical to run, if you’ve checked all else, start looking at what drives it.
 

NoQuarter

Major
Nov 24, 2017
1,599
996
0
Indiana, USA
Ride
Z4 35is, 535xi, X5 35i
Make sure the large battery cable that connects to the alternator is in the factory mounting tabs and routed as intended.

If it is left unattached and lays freely, it can get too close to the hpfp solinoid leads and affect the pwm signal. If the hpfp does not behave as expected, the DME will shut it down and turn the fan to max.

Similarly, check the HPFP solinoid connector for any corrosion or suspect wire issues.

Jim
 
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doublespaces

General of the Army
Oct 18, 2016
8,943
4,150
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AZ
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2009 E93 335i
Make sure the large battery cable that connects to the alternator is in the factory mounting tabs and routed as intended.

If it is left unattached and lays freely, it can get too close to the hpfp solinoid leads and affect the pwm signal. If the hpfp does not behave as expected, the DME will shut it down and turn the fan to max.

Similarly, check the HPFP solinoid connector for any corrosion or suspect wire issues.

Jim

Oh really? Do you have more information on how you discovered that? I'm starting to think my cable isn't in the original position, have to go check now.
 

NoQuarter

Major
Nov 24, 2017
1,599
996
0
Indiana, USA
Ride
Z4 35is, 535xi, X5 35i
Oh really? Do you have more information on how you discovered that? I'm starting to think my cable isn't in the original position, have to go check now.
First hand experience during my HPFP experiments with the piston style pumps and the stock rotary style.

When I put it back to stock I was missing the factory cable holders so left the cable whereever it rested. I couldn't get the stock HPFP working correctly so assumed I ruined the solenoid at some point. Turns out the solenoid was OK afterall and moving the battery cable away from the hpfp seems to have been the culprit.
 
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