N54 having LPFP spikes over 110psi!

A

alvinhobh

Private
Mar 8, 2018
49
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Columbia, Maryland
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2007 335i e92 6MT
N54 having LPFP spikes over 110psi!

2007 335i e92
Fuel-it stage 3 LPFP
550 cc PI
AIC2
Motiv- FF sensor
Running e85

In the process of tuning my car, noticed the LPFP pressure was all over the place, dropping below 40 and spikes over 100psi, so I decided to replace the following:

HPFP ( FCP lifetime warranty so why not)
HPFP sensor
LPFP sensor
Both LPFP filters
Driver side tank filter/ regulator tank
Removed and blocked off the stock FPR
Install an external FPR
Replaced the EKP ( used on from Ebay, coded with protool)

Pressure doesnt drop as lowe as before but still like crazy spikes! Tuner is working with me on this, giving me above and beyond support. He lowered the boost target so we can how things behave and I don't need help on analyzing anything in the log, but I wanted to put it out here and see if anyone has ever experienced the same issue with the LPFP spikes.



Created with Highcharts 7.1.1Amb pressure (PSI)Accel Ped. Pos. (%)Boost mean (PSI)Boost setpoint (-)Boost target (PSI)Cyl1 Timing Cor (*)Cyl2 Timing Cor (*)Cyl3 Timing Cor (*)Cyl4 Timing Cor (*)Cyl5 Timing Cor (*)Cyl6 Timing Cor (*)Ethanol Content (%)Fuel low pressure sensor (PSI)Fuel mode (-)Gear (-)IAT (*F)Lambda bank 1 (AFR)Lambda bank 2 (AFR)Load actualLoad req.MAF Req (wgdc) (g/s)Rail pressure (PSI)RPM (RPM)STFT 1 (%)STFT 2 (%)Throttle PositionTiming Cyl. 1 (*CRK)Torque actual value (Nm)Torque Lim. activeWGDC After PID (%)WGDC Base Value (%)MHD version 1.92 I8A0S FF AlvaroH Twisted Tune RB_NextGens_93oct_E85_AIC2V_v0.22_FF.mhd01.0K2.0K3.0K4.0K5.0K6.0K7.0K8.0KDatagraphs by SpoolStreet.com
 
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iminhell1

iminhell1

Sergeant
Jun 17, 2018
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How is the second pump triggered? powered?

The relief valve on the 274 is 112psi. The 267 is 85psi.


I'm running a 267 as my primary pump. A 274 as my secondary, triggered at 6psi. After it's triggered I hold right about 100psi. But I'm not sure the LPFP sensor can read any higher.
 
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A

alvinhobh

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Mar 8, 2018
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Columbia, Maryland
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2007 335i e92 6MT
2nd pump is triggered by a hobb switch, kicks on at about 12 psi, turning on a replay which pulls power straight from the battery.

So under load you are holding 100psi? I was under the impression anything about 80-90 was too much for the lowside fuel
 
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Cruizinmax

Corporal
Jul 18, 2018
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09 335i
What kind of external fpr are you running? If it can't keep the pressure below the set point that means it's unable to bypass enough fuel. Some regulators have different sized orfices for the return. You'll need to either allow the regulator to return more fuel or lower the volume of fuel you are sending to it.

Is it possible that the regulator just isn't set appropriately? Perhaps the base pressure is set too high?
 
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alvinhobh

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Mar 8, 2018
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Columbia, Maryland
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2007 335i e92 6MT
I have tried setting it from 45psi all the way to 70psi. Either end I see spikes over 100.

using the Racetronix FPR
REG-FI10106BS

Fuel Pressure Regulator, -10 / -6 AN E85, Black/Silver (REG-FI10106BS): Regulators - Fuel Injection

Purchase Fuel Pressure Regulator, -10 / -6 AN E85, Black/Silver or shop other Regulators - Fuel Injection and Racetronix products.
www.racetronix.biz www.racetronix.biz

Here is a log when I set it to 72 psi idle

Created with Highcharts 7.1.1Amb pressure (PSI)Accel Ped. Pos. (%)Boost mean (PSI)Boost setpoint (-)Boost target (PSI)Cyl1 Timing Cor (*)Cyl2 Timing Cor (*)Cyl3 Timing Cor (*)Cyl4 Timing Cor (*)Cyl5 Timing Cor (*)Cyl6 Timing Cor (*)Ethanol Content (%)Fuel low pressure sensor (PSI)Fuel mode (-)Gear (-)IAT (*F)Lambda bank 1 (AFR)Lambda bank 2 (AFR)Load actualLoad req.MAF Req (wgdc) (g/s)Rail pressure (PSI)RPM (RPM)STFT 1 (%)STFT 2 (%)Throttle PositionTiming Cyl. 1 (*CRK)Torque actual value (Nm)Torque Lim. activeWGDC After PID (%)WGDC Base Value (%)MHD version 1.92 I8A0S FF AlvaroH Twisted Tune RB_NextGens_93oct_E85_AIC2V_v0.22_FF.mhd-500501001502002501.0K1.5K2.0K2.5K3.0K3.5K4.0K4.5K5.0KDatagraphs by SpoolStreet.com
 
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Cruizinmax

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Jul 18, 2018
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That regulator should be able to bypass enough fuel. How is the regulator plumbed in? Regulator under the hood using factory feed, -6 return back to the tank? Do you have the vacuum reference on the regulator connected to anything?
 
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alvinhobh

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Mar 8, 2018
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Columbia, Maryland
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2007 335i e92 6MT
I’m using this FPS filter/FPR. The vacuum reference is connected to the manifold on the log above.


Upgraded fuel lines originally bought from fuel-it, and now the return line going to the top hat of the passenger side tank from FPS, ( I have to check the side of the hose, I believe it’s an -8an)


Plug, and Play E9X/E8X External Filter/FPR kit

PFS is proud to offer the most complete external filter/FPR kit on the market. With this kit utilizing our fuel line upgrades, you can simply bolt on the perfect fueling solution for high powered applications all in one compact unit. This kit includes our 10 micron Billet CNC filter, Fuel...
performancefuelingsolutions.com
 
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alvinhobh

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Mar 8, 2018
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Columbia, Maryland
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2007 335i e92 6MT
Here is a log before I replaced any of the components from the initial post, so stock FPR. I had spikes with the stock FPR

Created with Highcharts 7.1.1Amb pressure (PSI)Accel Ped. Pos. (%)Boost mean (PSI)Boost target (PSI)Cyl1 Timing Cor (*)Cyl2 Timing Cor (*)Cyl3 Timing Cor (*)Cyl4 Timing Cor (*)Cyl5 Timing Cor (*)Cyl6 Timing Cor (*)Ethanol Content (%)Fuel mode (-)Gear (-)IAT (*F)Lambda bank 1 (AFR)Lambda bank 2 (AFR)Load actualLoad req.MAF Req (wgdc) (g/s)Rail pressure (PSI)RPM (RPM)STFT 1 (%)STFT 2 (%)Throttle PositionTiming Cyl. 1 (*CRK)Torque actual value (Nm)Torque Lim. activeWGDC After PID (%)WGDC Base Value (%)MHD version 1.92 I8A0S FF AlvaroH Twisted Tune RB_NextGens_93oct_E85_AIC2V_v0.20_FF.mhdBoost setpoint (-)Fuel low pressure sensor (PSI)01.0K2.0K3.0K4.0K5.0K6.0K7.0K20406080100120140Datagraphs by SpoolStreet.com
 
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martymil

martymil

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JBacon335 said:
the vacuum reference is making it bring pressure up as boost rises. For our fuel systems I would recommend running it without manifold reference and just set it to 75 and forget it.
Click to expand...

100% you do not connect the boost reference line, set the base pressure when the motor is not running.

Easiest way to set base pressure is using the prime fuel pump feature using protools so the ekp is not adjusting your fuel pressures, prime the pump and it will do this for 2 min and adjust your FPR to 75psi.

You will never see a spike again over what you set.
 
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alvinhobh

Private
Mar 8, 2018
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Columbia, Maryland
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2007 335i e92 6MT
martymil said:
100% you do not connect the boost reference line, set the base pressure when the motor is not running.

Easiest way to set base pressure is using the prime fuel pump feature using protools so the ekp is not adjusting your fuel pressures, prime the pump and it will do this for 2 min and adjust your FPR to 75psi.

You will never see a spike again over what you set.
Click to expand...


I did exactly what you described.. used protool to prime the pump with the car off, set it to 75 psi. Disconnected the vacuum reference from the manifold, but still spiking...

Created with Highcharts 7.1.1Amb pressure (PSI)Accel Ped. Pos. (%)Boost mean (PSI)Boost setpoint (-)Boost target (PSI)Cyl1 Timing Cor (*)Cyl2 Timing Cor (*)Cyl3 Timing Cor (*)Cyl4 Timing Cor (*)Cyl5 Timing Cor (*)Cyl6 Timing Cor (*)Ethanol Content (%)Fuel low pressure sensor (PSI)Fuel mode (-)Gear (-)IAT (*F)Lambda bank 1 (AFR)Lambda bank 2 (AFR)Load actualLoad req.MAF Req (wgdc) (g/s)Rail pressure (PSI)RPM (RPM)STFT 1 (%)STFT 2 (%)Throttle PositionTiming Cyl. 1 (*CRK)Torque actual value (Nm)Torque Lim. activeWGDC After PID (%)WGDC Base Value (%)MHD version 1.92 I8A0S FF AlvaroH Twisted Tune RB_NextGens_93oct_E85_AIC2V_v0.22_FF.mhd01.0K2.0K3.0K4.0K5.0K6.0K7.0KDatagraphs by SpoolStreet.com
 
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RNM

RNM

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Jun 3, 2019
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Not to thread jack, but I am facing a similar problem. Hope we all get this resolved..

Created with Highcharts 7.1.1Amb pressure (PSI)Accel Ped. Pos. (%)Boost (PSI)Boost target (PSI)Cyl1 Timing Cor (*)Cyl2 Timing Cor (*)Cyl3 Timing Cor (*)Cyl4 Timing Cor (*)Cyl5 Timing Cor (*)Cyl6 Timing Cor (*)Fuel low pressure sensor (PSI)IAT (*F)Lambda bank 1 (AFR)Lambda bank 2 (AFR)Load actualLoad req.MAF Req (wgdc) (g/s)Rail pressure (PSI)RPM (RPM)STFT 1 (%)STFT 2 (%)Throttle PositionTiming Cyl. 1 (*CRK)Torque actual value (Nm)VANOS Ex. Act (*CRK)VANOS Ex. Req (*CRK)WGDC After PID (%)WGDC Bank 1 (%)WGDC Base Value (%)MHD version 1.92 IJE0S 1586805310828_BQE45RB IJE0S 6AT v3h.mhd657075808590951001.0K2.0K3.0K4.0K5.0K6.0K7.0KDatagraphs by SpoolStreet.com


2007 335i
Helix overdrive
Fuel it walbro 525 lpfp
EOSpeed bpm4 controller
Precision Raceworks Fuel regulator assembly with upgraded - 8an fuel line
 
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martymil

martymil

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alvinhobh said:
I did exactly what you described.. used protool to prime the pump with the car off, set it to 75 psi. Disconnected the vacuum reference from the manifold, but still spiking...

Created with Highcharts 7.1.1Amb pressure (PSI)Accel Ped. Pos. (%)Boost mean (PSI)Boost setpoint (-)Boost target (PSI)Cyl1 Timing Cor (*)Cyl2 Timing Cor (*)Cyl3 Timing Cor (*)Cyl4 Timing Cor (*)Cyl5 Timing Cor (*)Cyl6 Timing Cor (*)Ethanol Content (%)Fuel low pressure sensor (PSI)Fuel mode (-)Gear (-)IAT (*F)Lambda bank 1 (AFR)Lambda bank 2 (AFR)Load actualLoad req.MAF Req (wgdc) (g/s)Rail pressure (PSI)RPM (RPM)STFT 1 (%)STFT 2 (%)Throttle PositionTiming Cyl. 1 (*CRK)Torque actual value (Nm)Torque Lim. activeWGDC After PID (%)WGDC Base Value (%)MHD version 1.92 I8A0S FF AlvaroH Twisted Tune RB_NextGens_93oct_E85_AIC2V_v0.22_FF.mhd01.0K2.0K3.0K4.0K5.0K6.0K7.0KDatagraphs by SpoolStreet.com
Click to expand...

Mount your lpfp sensor on the reg where you would normally run a fuel pressure gauge.
 
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doublespaces

doublespaces

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Oct 18, 2016
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martymil said:
Easiest way to set base pressure is using the prime fuel pump feature using protools so the ekp is not adjusting your fuel pressures, prime the pump and it will do this for 2 min and adjust your FPR to 75psi.
Click to expand...

Does this send 100% DC to the EKP?

alvinhobh said:
I did exactly what you described.. used protool to prime the pump with the car off, set it to 75 psi. Disconnected the vacuum reference from the manifold, but still spiking...
Click to expand...

Can you take a photo of the tightening screw so we can see how far you have it cranked down? Have you tried loosening it a bit below 75 PSI at idle to see how that works?
 
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