[BSM n54iS]

So I'm gonna need some new leather seat cleaner cuz I just shit myself earlier.

Have been running v8 stage 2+ since forever, v7 before that etc. I wanted to flash back to 7.1 from v8, only other thing I changed was putting cold start back on. I had it turned off for a little over a month only. Put the RB external on with stock flapper hose (no head port plugs yet). After flashing the car stumbled like absolute crazy, finally about 10 seconds later the cold start kicked in and then reduced engine power and fan went max. I just changed the water pump ~5k ago, hence the . Turned off and flashed back to v8 but stage 0, with cold start and no problems at all. WTH happened?! That's a first for me.

[BSM n54iS]

So my car does NOT like cold starting at all now, still on stage 0 and it was stuttering for a few seconds before cold start kicked in. I know it's not misfire related, plugs and injectors are brand new with coils at 50% life, no codes and drives fine. Feeling like my o2 sensors are starting to go

[iqraceworks]

What do you mean coils are at "50% life"??

Also...if it was me, I would pull the plugs after letting the car sit overnight...see if any injectors are leaking. Are the injectors new BMW...or "new" remanufactured ones?

Welcome to the N54.....get used to troubleshooting issues, it's pretty common with these motors.

[BSM n54iS]

Originally Posted by iqraceworks

What do you mean coils are at "50% life"??

Also...if it was me, I would pull the plugs after letting the car sit overnight...see if any injectors are leaking. Are the injectors new BMW...or "new" remanufactured ones?

Welcome to the N54.....get used to troubleshooting issues, it's pretty common with these motors.

I mean these Eldor's have about half the miles put on them for a recommended maintenance fbo life. They are Index 12 replaced under extended warranty by BMW. I've owned the car for 80k about 50k of which stage 2 tuned. I'm used to it.

[iqraceworks]

Why are you running a stage 0 tune if the car has the Bolton's for a stage 2 tune? Have you tried going back to a stage 2 tune?

What else changed? You said you installed the RB extremal PCV setup? Could you have a vacuum leak somewhere? Or have something not installed right?

[BSM n54iS]

Originally Posted by iqraceworks

Why are you running a stage 0 tune if the car has the Bolton's for a stage 2 tune? Have you tried going back to a stage 2 tune?

What else changed? You said you installed the RB extremal PCV setup? Could you have a vacuum leak somewhere? Or have something not installed right?

B/c stage0 is stock tune and not as aggressive. Nothing else changed dude, no leaks. Car is close to 110k and on original o2 sensors, rough cold start and foul exhaust smell are only symptoms. I drove hard enough to know there is no boost leak, no codes.

[Saif2018]

Originally Posted by BdSM n54iS

B/c stage0 is stock tune and not as aggressive. Nothing else changed dude, no leaks. Car is close to 110k and on original o2 sensors, rough cold start and foul exhaust smell are only symptoms. I drove hard enough to know there is no boost leak, no codes.

Seems a bit of a waste to have Boltons for stage 2 and running without a tune.

If your car doesn't like cold start, you can disable cold starts using MHD
Personally only ran V9 and V7.1 (current map) never had any issues with them.

My car in fact runs better with cold start on.

Only time idle went crazy is when I reset the throttle adaptations and didn't wait 30 seconds before starting the car up, easily resolved.

[BSM n54iS]

Please read OP

[iqraceworks]

With DP's (and the other bolt ons).....doesn't it need to be on a stage 2 tune to even run right? The stock fuel/spark tables are not setup for any mods....... especially not DP's.

[Saif2018]

Originally Posted by BdSM n54iS

Please read OP

I did, if its running fine without cold start, have you tried flashing a tune without cold start?

Are you saying v7.1 and V9 with or without cold start, don't run properly in your car but V8 which has been reported by many people to be problematic does?

[BSM n54iS]

Originally Posted by Saif2018

I did, if its running fine without cold start, have you tried flashing a tune without cold start?

Are you saying v7.1 and V9 with or without cold start, don't run properly in your car but V8 which has been reported by many people to be problematic does?

I've been running MHD stage 2+ for a few years. Cobb before that. Been on v8 stage 2+ for a long time. A while ago I took cold start off just for a break... STILL on stage 2+! Put external pcv on. Flashed to 7.1 stage 2+ but with cold start turned back on again only after having it off for a month or two. CAR FREAKED. Flashed to v8 stage 0 for the first time! With cold start and still unhappy. I need new o2 sensors.

[CarAbuser]

O2 sensors wouldn't make a difference for cold start. Runs open loop until warmup routine is complete.

[Saif2018]

Originally Posted by BdSM n54iS

I've been running MHD stage 2+ for a few years. Cobb before that. Been on v8 stage 2+ for a long time. A while ago I took cold start off just for a break... STILL on stage 2+! Put external pcv on. Flashed to 7.1 stage 2+ but with cold start turned back on again only after having it off for a month or two. CAR FREAKED. Flashed to v8 stage 0 for the first time! With cold start and still unhappy. I need new o2 sensors.

I doubt its the map, v7.1 is known to be reliable, and I've been running it since I tuned my car with cold starts. What about V9 with cold start?

[BSM n54iS]

Originally Posted by CarAbuser

O2 sensors wouldn't make a difference for cold start. Runs open loop until warmup routine is complete.

https://www.e90post.com/forums/showthread.php?t=1087508

Originally Posted by Saif2018

I doubt its the map, v7.1 is known to be reliable, and I've been running it since I tuned my car with cold starts. What about V9 with cold start?

Wasn't interested in trying out another beta map for no reason, v7 or v8 ots is totally fine for me while I'm updating car with new mods.

[RoughKnight]

Sometimes this happens to me, usually during a slightly low battery charge cycle. Usually if I hear the fan ill turn the car off and reflash, that fixes it.

7.1 Changes some of the internal settings, i can't tell you exactly what but my car always reacted weird on 7.1. Have you tried 9.0 stg2? Leave the cold start on, and try driving it around for a few days and see if that fixes everything.

[CarAbuser]

Originally Posted by BdSM n54iS

https://www.e90post.com/forums/showthread.php?t=1087508

During cold start no fuel trims are active and the car runs fuel mode 4 or 5 depending on the phase of the heating routine which is double injection.

I don't know what makes you think your O2 sensors need replacing but if that's your attitude to people helping you then go knock yourself out with new parts.

[Emilime75]

If I'm reading your posts correctly, your problem started directly after installing the external PCV while simultaneously flashing 7.1 with Cold Start On. Is this correct?

Did you run the car after the PCV install, but before the 1st flash after installing the PCV?

What did you use as your vacuum reference/OCC return for the external PCV? Was it RB's throttle body adapter, or did you drill/tap a port somewhere?

[BSM n54iS]

Originally Posted by Emilime75

If I'm reading your posts correctly, your problem started directly after installing the external PCV while simultaneously flashing 7.1 with Cold Start On. Is this correct?

Did you run the car after the PCV install, but before the 1st flash after installing the PCV?

What did you use as your vacuum reference/OCC return for the external PCV? Was it RB's throttle body adapter, or did you drill/tap a port somewhere?

1. Yes
2. No. Was flashed on v8 stage 2+ (no cold start) during install meaning was running that before as well.
3. RB adapter. No head ports plugged.

Didn't change anything from yesterday and just ran some errands. No cold start issue now, still v8 but stage0. Will put stage 2+ back on with v8 and see. I'm perplexed again now. Car has 110k original o2 sensors with many miles tuned so that's what I was really leaning towards, them just on the cusp of starting to go bad.

[Emilime75]

Curious, I'm not tuned, so I don't know...does a map flash reset fuel trims? Is it possible you've had a mild, underlying issue that the DME has been able to adapt to making it unnoticeable? Maybe, if it does, is why you experienced issues after the flash and now the DME is beginning to adapt again?

[feuer]

Originally Posted by BdSM n54iS

I mean these Eldor's have about half the miles put on them for a recommended maintenance fbo life. They are Index 12 replaced under extended warranty by BMW. I've owned the car for 80k about 50k of which stage 2 tuned. I'm used to it.

Who made this dumb recommendation? Would 5k hwy vs 5k city vs 5k track yield equal life span? Just curious....

[BSM n54iS]

Originally Posted by feuer

Who made this dumb recommendation? Would 5k hwy vs 5k city vs 5k track yield equal life span? Just curious....

Lol the OP who drives the car and knows they type of miles they put on their car

But don't worry, I'm getting new coils from FCP for lifetime and change them with oil soon for the hell of it so everybody can sleep easy at night that my coils will be brand new as well

[roadkillrob]

There have been a few other posts in the last year or so I have read with weird issues after turning cold start off and back on - maybe see if you can find them, seems there is some weirdness around changing cold start on some cars.