Big build going crazy I’m about to give up

[Eailva94]

So I'm going to list everything I have added to my car first.



Dinan Intake

Dinan Exhaust

Dinan Intercooler

Bigboost turbo kit stage 3.4 (capable of 800 hp)

VSRF charge pipe

Stage 3 LPFP

S55 Dual HPFP for N55 from Tuning Tech by Frank Smith

Fuel-it Port injection with 950cc injectors

xHP Stage 3 tranny flash

KW Coil overs

Brembos big break kit (front and rears)

M-Performance LSD

Full E85



After three long months I finally was able to get my car running with my new HPFP running via flash through MHD (not needing a controller) everything was running fine still need to do some more tuning to get to my power goal which is around 650 whp. So yesterday I was on the highway and i had a little less then a quarter tank of gas (E85) and i get a drivetrain malfunction. I pull over to the side of the highway to a stop and I turn the car hoping to reset everything. So I do just that and I attempt to try and turn it back on and it starts to hesitate as if it wants to crank up but it isn't. It sounded as if i ran out of gas. I call my wife and i have her take me to get some gas. I put the 2 gallons of gas in and I try to start it up. It hesitated to turn on literally for maybe 2 seconds and it started up. I head to the gas station to fill the car up and I go home. So this morning i leave my house with a full tank and I had about an hour and half drive to work and I was driving aggressively because I was enjoying having my car back after three months of not being able to drive it. So i get to work then my lunch break comes up so I get in my car and I try to crank it up and it starts to hesitate like it did yesterday. But this time I know I have gas. I keep trying to get it to turn on and after a couple times of pressing the ignition it finally turns on. This has become very stressful now because it seems like every time I get my car back it seems to always bring me problems. I'm hoping someone can give me a little insight/opinions on what could be possibly going wrong. I'm going to post the video of the first occurrence yesterday and the video of today during my lunch break.

^^Highway breakdown^^

^^Lunch time fuck up^^

 

[NoQuarter]

What is the fuel pressure prior to attempting to start it?

 

[Bnks334]

codes? log? is this a bucketless setup?

 

[Rob09msport]

That sounds like what happens when a n54 or early n55 hpfp fails. I know you are n55 with the dual pumps. Fist question would be do you have cold start disabled and you need take log like others mentioned above. You also could try running pump flash and gas but it really would seem to be hpfp related considering you got the half engine as well.

 

[9krpmrx8]

Yeah man, you need to verify your low fuel pressure and the N55 doesn't have a LPFP sensor so you will have to do that at a shop or rig something up to test it.

 

[NoQuarter]

Yeah man, you need to verify your low fuel pressure and the N55 doesn't have a LPFP sensor so you will have to do that at a shop or rig something up to test it.

The high pressure sensor should show ~70psi prior to starting the engine

 

[9krpmrx8]

Yeah but that won't tell you what it is doing while running.

 

[doublespaces]

How is your stage 3 pump plumbed/wired? Maybe something is wrong with it. Need to see if there is pressure somehow. What a bummer that some n55's don't have a sensor there?

These issues could be entirely separate. We need to know how much fuel you put in at the pump after you ran out of fuel.

 

[Weehe]

I thought BMW added the LPFP sensor back into some F series N55s. Was the E series that don't have them.

 

[9krpmrx8]

I thought BMW added the LPFP sensor back into some F series N55s. Was the E series that don't have them.

I know my E90 did not so I tapped the line where the stock sending unit goes on N54's. But I looked up a VIN for a 2014 335i on realoem.com and I can't find a sensor.

 

[matreyia]

If you have flex fuel that module.may be dead. That's what happened to me a while back. If no ff then perhaps a bad hpfp or lpfp or the ekpm is on the way out.

 

[Rob09msport]

Elephant in room ...... highly custom s55 fuel system and pi . Try to trigger the half engine eff m again and scan the code. The code should still be in history if you haven't cleared.

 

[mfractal]

I had a hard time starting up the car initially with the helix Hpfp. Tuner had to try a few different revisions to fix it. What happened is it generated too much rail pressure during startup. Not saying it’s your issue but it might be something to look into.

 

[Eailva94]

I had a hard time starting up the car initially with the helix Hpfp. Tuner had to try a few different revisions to fix it. What happened is it generated too much rail pressure during startup. Not saying it’s your issue but it might be something to look into.

What do you think about the helix pump? Are you satisfied with it? And what else do you have running on the car? Port injection ?

 

[mfractal]

What do you think about the helix pump? Are you satisfied with it? And what else do you have running on the car? Port injection ?

I previously had 7 nozzle PI system which I in all honesty hated and removed. Now I only run a Walbro 450 in tank and the helix pump.
I didn’t see it’s whole potential yet since i am on a lowish boost file (we are still figuring out fueling) but I already saw that it holds pressure above stock which is to be expected. Installation was a breeze according to my mechanic and other than the cold start issues initially which have almost been mitigated it feels exactly like oem but provides higher rail pressures. I’m pwg and I find I can’t hold more than 19-20 psi to red line. Once I get there with current setup I’ll post logs here if you’re interested. Shouldn’t be long now.
David shoup is my tuner btw.

forgot to mention - we are going for e45-e50.