[Icey]

So I’m running stage 2+ (93 octane tune) FBO on my 2015 435i 8 speed stage 3 XHP
yesterday I went to go fill up on 93 octane gas and later in the day I’m leaving my neighborhood come to a complete stop, and my cars rpm drop and the cars about to stall but it doesn’t after that the whole day the car was fine, fast forward to today I’m driving maybe 10 min come to a complete stop car stalls start it up drives completely fine the whole day, any ideas ? LPFP? Bad fuel? Fuel rail pressure seems to be hitting 1300 on idle and over 2k on while driving

[thejeremyman9]

No codes in kinda weird if it stalled. Log WOT 4th gear pull and make sure fuel pressure holds. If the stalling is recurring/repeatable, try and log or at least monitor fuel pressure live and see if the car stalls because it loses fuel pressure.

If it only happens after getting gas there is the fuel tank vent valve thing but i am not sure if that causes these exact issues

[Icey]

Originally Posted by thejeremyman9

No codes in kinda weird if it stalled. Log WOT 4th gear pull and make sure fuel pressure holds. If the stalling is recurring/repeatable, try and log or at least monitor fuel pressure live and see if the car stalls because it loses fuel pressure.

If it only happens after getting gas there is the fuel tank vent valve thing but i am not sure if that causes these exact issues

Fuel pressure holds perfectly fine on 4th gear WOT, and did a run of 1-4th WOT no dips in fuel pressure

[BeastMode335i]

Originally Posted by Icey

Fuel pressure holds perfectly fine on 4th gear WOT, and did a run of 1-4th WOT no dips in fuel pressure

Did you fix this? I'm having the same issue all of a sudden.

[Zprado]

Originally Posted by Icey

So I’m running stage 2+ (93 octane tune) FBO on my 2015 435i 8 speed stage 3 XHP
yesterday I went to go fill up on 93 octane gas and later in the day I’m leaving my neighborhood come to a complete stop, and my cars rpm drop and the cars about to stall but it doesn’t after that the whole day the car was fine, fast forward to today I’m driving maybe 10 min come to a complete stop car stalls start it up drives completely fine the whole day, any ideas ? LPFP? Bad fuel? Fuel rail pressure seems to be hitting 1300 on idle and over 2k on while driving

Update on your issue ?

[fast135i91]

Hello,

I am having the same issue. Same code 21a023. Same engine stall once I approach a red light and idle for a few seconds. Auto start stop disabled.

My 2015 335i started randomly stalling at idle after driving for at least 15-20 minutes. For instance, I drive for 15-20 minutes or more, and then stop at a red light, and after 10-15 seconds of idling, the car lightly stalls and kicks into Neutral gear position. Auto start/stop is off. And computer threw a few codes but did not set CEL (see pic). (Lightly stalls meaning no rough jerk with stall).

Also interesting, is that after it lightly stalls, it starts right back up no hesitation. No limp mode. No half engine light. No other symptoms. Full power is available. It stalled with BM3 OTS stage 1 ACN map. And it also stalls with stock map. Engine oil full. Gas above 1/2 tank, Chevron 91octane. No coolant leaks. No oil leaks. No overheating. No unusual noises.

Checking sensor data, alternator output is 25+ amps. Battery voltage is 14.5-14.7v while running. Battery state of charge is 98%. Again, no misfire nor driveability issues. This just started happening, and since it is my daily, I’d like to fix it as soon as possible. I was initially going to wait for a CEL to turn on if the problem got more consistent or worse.

128k fantastic miles. Stock intake. Catless DP.

Checked engine air filter and it’s dry and clean.
Checked around engine bay and no chewed wires or anything.

I was thinking it could be a EKPM3 or fuel pressure sensor since those both could possibly be faulty without setting a CEL. Just a guess.

Any thoughts?

Thanks in advance.