[E90Montego335]

Hey everyone out of nowhere today my car wouldn't start no matter how many tries. It cranks and cranks but won't start. Got code 29F3 which indicates low pressure fuel sensor but reading other stories it doesn't seem like that would cause the car to not start? Kinda stuck now as I don't 100% know if it's possible a hpfp or lpfp or the sensor. Anybody have experience with this?

Also should add I have the 2AAF fuel pump code but I've had that for a year or two which I've read is pretty common. Thanks

[E90Montego335]

Kind of desperate here now guys. Just replaced my lpfp sensor and still long cranks with no starts. Thought maybe it could be due to MHD since the issue started the same day I installed a BEF. Flashed it back to stock and nothing.

Read the codes and I have 2FCA & 2FDA as shadow codes which I think are related to the hpfp but reading online some have said it’s normal to have those. I tried clearing them and reset all adaptations with no help. If it’s the hpfp or lpfp I don’t mind changing them myself but I just wanna know exactly what is the issue so I don’t throw parts at it. Any help is appreciated.

[zomski101]

Is your lpfp priming when you unlock or open the door?
Monitor your rail pressure and lpfp psi with mhd.
If you have inpa try this video below

[E90Montego335]

Originally Posted by zomski101

Is your lpfp priming when you unlock or open the door?
Monitor your rail pressure and lpfp psi with mhd.
If you have inpa try this video below

Oddly enough I found that video shortly after my post. My pump isn’t priming (that I can hear) and when I did the test my rail pressure is showing zero. Just to make sure I even did the test with my brothers 335 and his pressure was normal.

Probably a dumb question but is that like a 100% bad lpfp? I’ve read about the relays going bad too but not sure exactly if the inpa test has anything to do with that. Tomorrow I’m going to try switching his lpfp into mine and see if that works anyway. Also should add I’ve been running a 3-4 gallons of e85 on my stock pump so wouldn’t surprise me if that killed it. (Dumb I know)

[zomski101]

You can try to hot wire the lpfp. If it works it could be the ekg.

[E90Montego335]

Originally Posted by zomski101

You can try to hot wire the lpfp. If it works it could be the ekg.

Well quick update just swapped out the lpfp and still long cranks and no start. Even after the swap still not hearing the pump prime and the inpa test still shows no rail pressure. Getting dme codes now also. Not sure if it’s anything but when I put my key in and press the button once a loud sort of buzzing sound is coming from where the hpfp is located. It goes on for minutes until I lock the car which I’ve never heard before. I know waterpumps make a similar sound but am pretty confident it’s not the water pump.

Plan on swapping the fuel pump relay next and then the hpfp

[E90Montego335]

Pretty depressing update. Swapped out the hpfp and still no start. So I’ve changed the lpfp, lpfp sensor, fuel pump module and the hpfp and I’m out of ideas. I’m still getting the 29F3 sensor code (no clue why) and 2FCA/2FDA codes. Can still hear a buzzing electrical noise the second I turn ignition on and it doesn’t go away till I take the key out. Maybe it’s something dme related have no clue at this point.

[Lucas_335i]

did you find out what the problem was?