Help with cold start

mfractal

Specialist
Nov 10, 2017
80
27
0
Ride
E90 Sedan LCI 335i FBO MHD E40
Hey guys, been having this intermittent cold startup failure that i can't pinpoint for more than a year now.

F10 535i.

Relevant Mods : Spool Stage 2 hpfp, walbro 450, turbo upgrade, E60, custom tune.

Symptoms :
- ONLY happens on a cold start, like really cold, if i drove the car in the morning for a few minutes it won't happen if i start it in the night, only the next morning.
- Been happening all the time about a year ago and slowly disappeared by itself (adaptations ?)
- Recently i flashed a new map (which required a long write and i guess reset adaptations) and the problem came back. Note - the new map didn't change anything about the cold start procedure, it was a boost adjustment on high gear update.
- Here's a log showing the issue (3 logs there), rail pressure seems normal. wish i had a lpfp sensor https://datazap.me/u/mfractal/no-start-3-logs?log=0&data=17-18
- My mechanic is basically throwing his hands in the air.


Any suggestions ?

Thanks in advance.