[jb-slow]

My car stutters after a cold start, drive 100ft or so and it clears up. It started doing this after flashing the car with bm3 stage 2 ots tune. I've updated the tune to the 7.0 version out now and it made no difference. If I reset the adaptations the problem goes away but slowly returns and the car re-learns everything. I've narrowed it down in my head to the cold start being disabled (I believe) in the tune, if the car is warm there is no problem at all. Is there a way to enable the cold start again the the bm3 software? I use my laptop. Or is there something I'm missing?

[MidwayMuller]

Are you still on stock plugs and intake? I've seen both of these cause issues on Stage 2 cars.

[jb-slow]

Stock intake right now, I swapped out the cts intake that was on there but it didn't change anything. The plugs I believe are 1 step colder.

[Pray for Mojo]

There's a config icon on the top right when you click on the map. Use that menu to enable cold start, save at the bottom and reflash.

[jb-slow]

Thanks, I'll try that.

[OldCrow7xx]

Originally Posted by jb-slow

My car stutters after a cold start, drive 100ft or so and it clears up. It started doing this after flashing the car with bm3 stage 2 ots tune. I've updated the tune to the 7.0 version out now and it made no difference. If I reset the adaptations the problem goes away but slowly returns and the car re-learns everything. I've narrowed it down in my head to the cold start being disabled (I believe) in the tune, if the car is warm there is no problem at all. Is there a way to enable the cold start again the the bm3 software? I use my laptop. Or is there something I'm missing?

My other N55 did that and never learned why.

My current N55 does not do it, only difference I see if the PWG turbo vs. EWG turbo. Same bolts ons, tranny and tune.

These cars are so complicated its hard to say sometimes. People blamed the Berger Intake Kit, maybe it had something to do with it.

[jb-slow]

Well I turned the cold start option on and the car didn't have any issues today. It took 2-3 days of learning to make the stutter come back before so we'll see if it stays problem free in the next few days.

[illmatic37]

Is it possible that it has nothing to do with the tune? I was just gonna make a post about the same thing when I read your post.
I’m experiencing the same issue, stuttering right after start, but my car does it when it’s warm too. Also I warm up the car for about a minute from cold start. When it stutters, sometimes I’ll put it in second gear early and that seems to smooth it out. Mines is a 2014 m235i 6mt, all stock, 37,xxx miles. I first noticed it right after I filled gas, we have crappy 91 here in Hawaii. As soon as I started the car and pulled away from the pump it started to stutter, and almost died. When I started the car it was weird too, almost like a dead battery, super slow crank after pushing the start button. That’s only happened the one time though. My first thought was that I put some bad gas in the car.
Sorry about the long post, but I’m planning to stage 2 BM3 as well but I’d like to figure out the stutter first.

Originally Posted by jb-slow

My car stutters after a cold start, drive 100ft or so and it clears up. It started doing this after flashing the car with bm3 stage 2 ots tune. I've updated the tune to the 7.0 version out now and it made no difference. If I reset the adaptations the problem goes away but slowly returns and the car re-learns everything. I've narrowed it down in my head to the cold start being disabled (I believe) in the tune, if the car is warm there is no problem at all. Is there a way to enable the cold start again the the bm3 software? I use my laptop. Or is there something I'm missing?

[jb-slow]

Sounds like we have the same problem. Some of these cars are hyper sensitive to mods, others are not, mine being one of the sensitive ones. It absolutely hated the injen intake I put on it, it would stutter and surge while driving. I swapped out the intake to a cts turbo intake and that problem went away, but this new stutter problem slowly started over the next year until it got to where it consistently stuttered on cold starts. I know my car is a pain and maybe it's just too sensitive to have the cold start option turned off, I'm on day 2 now and it's been perfect since turning it back on. I have my fingers crossed that it stays that way and I'll report back in a few more days on the final verdict.

[MidwayMuller]

Originally Posted by jb-slow

Stock intake right now, I swapped out the cts intake that was on there but it didn't change anything. The plugs I believe are 1 step colder.

OK, do you know what type or brand the plugs are? I've seen the NGK iridiums help some tuned cars with this kind of stuff in the past. Hopefully the gap is all good on those, and all coils are snapped on tight. Both could easily cause this type of stutter.

I would also check the battery voltage to see if it's holding as it should, and make sure the MAF/MAP sensors are clean on the charge pipe and intake snorkel tube.

[jb-slow]

Everything has been fine so far, it's just one of those hyper sensitive cars. Turning on the cold start option seems to have fixed it.

[illmatic37]

Been thinking about this off and on, my other bmws are n/a so this is my first experience with a boosted bmw. Could the stuttering be fuel related? Once when it was doing the stuttering I gave it more gas and it felt like the motor was bogging. Never had a car with high pressure and low pressure fuel pumps so I’m not really familiar with the theory behind running 2 pumps. I’ve read a bunch of threads about this problem, most ask about air/air filter or plugs or coils. Never seen anything posted about fuel being a possibility. Anyone have any thoughts?

[jb-slow]

It was just shitting bricks because the cold start was turned off, its fine now that it's back on, I have one of the stupid super sensitive cars.