[Malteser_wfj]

Over the weekend I was flashing MHD stage 0 for linear throttle & lower coolant temp and accidentally interrupted/cancelled it mid way through by turning on airplane mode and losing wifi connection to the adapter....

Safe to say the car was PISSED and had a multiple of module errors.

I then successfully flashed back to stock however I have this weird issue with the fuel pump where an error pops up on the dash & idrive system, then the engine cuts out when on throttle in gear (doesn't stall) for about 0.5s then power comes back.

Most times the error resolves itself and the error goes away by itself, then comes back a minute or so later.

There are NO codes at all on the car so nothing pointing to anything wrong with the HPFP. No long crank, meets requested rail pressure when it does.

I've been able to record the problem on the below logs and it seems the issue is that the rail pressure stays higher than it should do when I'm off throttle, then dips when I go back on the throttle.

This is all being as smooth as I can be, and it does the cutting out way less often when I'm using cruise control interestingly.

Datalogs are here:
https://datazap.me/u/lemansn55/fuel-...og=0&data=4-19

https://datazap.me/u/lemansn55/fuel-...ata=2-17-18-19


Car is a 03/2012 335i manual

After the interrupted flash I could hear something running pretty consistently underneath the car which could have been the LPFP? The tank had between 1/8 and 1/4 fuel and the front was raised slightly as I was changing the oil.

Is it possible that air could have been introduced into the system somehow??? And is there a bleed procedure at all so I could rule this out?

Could the fuel pressure sensor possibly need changing?

As an aside - the interrupted flash was also giving me 28A0 and 2820 which I solved last night by doing the fuel tank purge valve reset, so the only issue is the fuel pump.

The error seems to come up on the dash & idrive during the higher than requested duration, and then dies off shortly afterwards so is the ECU telling the fuel pump to back off the pressure and that's why it's falling off?


Any help at all is greatly appreciated!! It's becoming a pain to have these big jerks when power comes back in after only 3 days

[Malteser_wfj]

Anyone have any idea what could cause this?

I replaced the fuel pressure sensor and flashed from MHD Stage 0 to remove MHD completely and still have the same problem.

Is it common for the HPFP to provide too much pressure when it's failing?

https://datazap.me/u/lemansn55/fuel-...19&zoom=26-217

[anjuna]

Where do you expect the pressure to go?

[Malteser_wfj]

I would expect it to follow to requested pressure like it does initially.

[Malteser_wfj]

For anyone interested the issue was the EKP module which needed recoding to factory.

The codes I got by looking through BimmerLink not MHD were:

6292 EKP motor voltage too low
6295 EKP engine power is missing

[wheela]

Thanks for following up with the solution. I never would have guessed EKP would be related to this issue, that just controls the lpfp, right? Is the theory it's coding got messed up when the flash got interrupted mid-way?

[Malteser_wfj]

Originally Posted by wheela

Thanks for following up with the solution. I never would have guessed EKP would be related to this issue, that just controls the lpfp, right? Is the theory it's coding got messed up when the flash got interrupted mid-way?

No I didn't expect it to either, but I was driving the car like that for 3+ weeks and wasn't getting the usual HPFP failing symptoms.

So, yeah my understanding is interrupting the flash messed something up within the EKP which control the LPFP.

It's interesting though, I hear the pump running for longer than ever before (going back months) now after I unlock the car which is good because it used to fire up, then some seconds later I'd hear the lpfp kick in again while idling so now it seems to prime with all the fuel it needs in advance.

The factory coding reset seems to have made the car run better overall too which is very interesting because it's completely stock and at 128k miles with neither pumps being replaced at any point.