[WajahatM]

Recently my car started having this issue where it starts, runs extremely rough with low RPM surges, then dies and goes to the "off" position on the tachometer. It's happened twice now, the first time it started and died like 4 times, only staying on if I gave it some gas, and sounded like it was misfiring without any misfire codes, kinda sounded like a carbureted engine. I flashed back to stock started driving anyways car still running rough/jerky acceleration, but then it corrected itself after like 1000 feet. The second time was after coming back to the car from the store, car started, surged, then died; it started up fine after that. Both times it threw the same codes. Car was also gunshot burbling when it was flashed back to stock, but that might've been because of the burble setting from bm3 and the ecu had to relearn or something. Does anyone know what the issue might be? I'll bring it up to service advisor to look at and I'll try to get some footage.

Visiting service advisor for current problems which might be unrelated: gear shift lever illumination going out, sunroof not closing unless reinitialized, and windshield fluid pump going out.

Recent changes include: bootmod3 transmission flash beta, full fluid changes (brake, coolant, diff, atf, transfer case, and oil), filled up with new gas in between the two incidents, ~500 miles ago emissions test with catsim postitapped into O2 sensor (postitaps still in place but catsim removed). I have an afe momentum with a dry filter, unplugged each coil to see if one was causing misfires, replaced sparks about 5000 miles ago one step colder, and had the lpfp recall done maybe 10-15k miles ago.

Any other tests or input would be appreciated from you guys!

[WajahatM]

So here's a video of what the problem looks like

The first 3 times it happened it threw the codes above. Then it happened when I was driving (flashed back to stock), it let out a couple of gunshot burbles, then quickly died, restarted, and went into limp mode

Any ideas? Gonna be dropping off to the dealership tomorrow

[Eschmacher]

Quick test you can do: unplug your MAF and see if the issue continues

[mlev]

I had almost an identical issue when I was buying Arco 91 octane. Switched to Chevron and it went away. Techron seemed to help my injectors. Had no codes and dealer couldn't replicate the issue. Yours seems to be a bit worse than mine but I wasn't tuned at that time.

Also try cleaning your MAF sensor with MAF cleaner.

[WajahatM]

I'll unplug my MAF and clean it to see if it makes a difference. Problem is that this issue doesn't happen every startup. I had a MAF issue before, got it replaced as I was using an oiled filter, now I have a dry filter.
Think it could be injectors? I can smell gasoline and the car gunshots randomly as well.

[mlev]

Originally Posted by WajahatM

I'll unplug my MAF and clean it to see if it makes a difference. Problem is that this issue doesn't happen every startup. I had a MAF issue before, got it replaced as I was using an oiled filter, now I have a dry filter.
Think it could be injectors? I can smell gasoline and the car gunshots randomly as well.

Yes could be injectors or bad gas.

[Eschmacher]

For sure, or coilpacks too.

[mikeycons]

Recent Bootmod3 update did this to me too. Turn cold starts back on

[WajahatM]

Originally Posted by mikeycons

Recent Bootmod3 update did this to me too. Turn cold starts back on

Hmm I did do the transmission flash, otherwise I'm PWG and haven't had an update since October

[Polo08816]

Originally Posted by mlev

Yes could be injectors or bad gas.

Probably bad injectors.

[WajahatM]

So took it to the dealer twice, first time they said I incorrectly installed the intake and it was leaking air, which was BS and it stalled again. Then they said my aftermarket chargepipe was loose, they test drove it twice, and now there's no codes.

I'm gonna pick it up today, but I wanted to ask if a loose chargepipe could cause my issues and throw lean/rich codes.

[XutvJet]

Originally Posted by WajahatM

, but I wanted to ask if a loose chargepipe could cause my issues and throw lean/rich codes.

Absolutely. Unmetered air entering the intake can cause stumbling, stalling, lean/rich conditions, etc.

[WajahatM]

Originally Posted by XutvJet

Absolutely. Unmetered air entering the intake can cause stumbling, stalling, lean/rich conditions, etc.

Thank you very much, hopefully the problem has been eliminated. I'll keep this thread posted.
If anything, the problem is so intermittent and elusive, I'll just wait for something to fail before taking it back in lol.

[XutvJet]

Originally Posted by WajahatM

Thank you very much, hopefully the problem has been eliminated. I'll keep this thread posted.
If anything, the problem is so intermittent and elusive, I'll just wait for something to fail before taking it back in lol.

If it comes back, you might want to go to an independent BMW shop as they tend to be more willing to troubleshoot. Dealership techs are often over-worked, tend to stick to be BMW procedures, and throw their hands in the air when they see mods.

[WajahatM]

Originally Posted by XutvJet

If it comes back, you might want to go to an independent BMW shop as they tend to be more willing to troubleshoot. Dealership techs are often over-worked, tend to stick to be BMW procedures, and throw their hands in the air when they see mods.

Makes sense to me, I gotta find a good shop near me then. If anyone knows somewhere good in the northwest suburbs of Chicago lmk.

[WajahatM]

Car hasn't stalled and I feel like it even runs smoother on idle. Strange how the chargepipe became loose after 40k miles, maybe when I got the coolant changed someone bumped it