[ev1l335]

Any guesses what could cause such issue on 335is MT?
After car is started (no matter hot or cold, time between hot starts does not matter also), idle is rough, after couple of seconds AFRs go to ~20s and stay there. Solution is to press accelerator pedal, hold it steady in one position, wait for 15-30 seconds and AFRs go back to normal and car can idle without issues. If I do not press accelerator that issue does not go away by itself.

Following errors are thrown from time to time: 2D2B & 2D2E. I have tried doing adaptations reset with ProTool and complete reflash of a car, neither helped. Recently a lot of tuning parts were installed, one of them rbturbo external PCV kit with head plugs was installed, since it is connect to throttle I think that it can have some effect.

I have uploaded a log that was recorded at the same time as a video:
https://datazap.me/u/voroninpy/335is...3&mark=342-482

[Saif2018]

Originally Posted by ev1l335

Any guesses what could cause such issue on 335is MT?
After car is started (no matter hot or cold, time between hot starts does not matter also), idle is rough, after couple of seconds AFRs go to ~20s and stay there. Solution is to press accelerator pedal, hold it steady in one position, wait for 15-30 seconds and AFRs go back to normal and car can idle without issues.

Following errors are thrown from time to time: 2D2B & 2D2E. I have tried doing adaptations reset with ProTool and complete reflash of a car, neither helped. Recently rbturbo external PCV kit with head plugs was installed, since it is connect to throttle I think that it can have some effect.

I have uploaded a log that was recorded at the same time as a video:
https://datazap.me/u/voroninpy/335is...3&mark=342-482

2D2B - DME: Intake-manifold pressure sensor, overrun

2D2E - Angle of throttle valve - intake pipe underpressure, correlation

Are you running JB4?

[ev1l335]

Originally Posted by Saif2018

2D2B - DME: Intake-manifold pressure sensor, overrun

2D2E - Angle of throttle valve - intake pipe underpressure, correlation

Are you running JB4?

No MHD with custom tune from Wedge but I also have the very same issue if I flash Stage2 which I used before installing tuning parts, so I think issue is not with a tune but something mechanical or some sensor acting up.

[Saif2018]

Originally Posted by ev1l335

No MHD with custom tune from Wedge but I also have the very same issue if I flash Stage2 which I used before installing tuning parts, so I think issue is not with a tune but something mechanical or some sensor acting up.

Have you emailed MHD for log analysis?

I would suggest you do so if you haven't, they should be able to point you in the right direction.

[Spacecpe]

Check the sensor on top of the intake manifold and clean it. Had a similar issue on cold starts where it would start at 14.8 and dive close to 20 and the car stalls.

[ev1l335]

Originally Posted by E90 M335i

Check the sensor on top of the intake manifold and clean it. Had a similar issue on cold starts where it would start at 14.8 and dive close to 20 and the car stalls.

Thank you for advice I will check it! Mine also stalls but only if I would drive it.

Originally Posted by Saif2018

Have you emailed MHD for log analysis?

I would suggest you do so if you haven't, they should be able to point you in the right direction.

No I did not, I did not know that they provide such service, but I will definitely try if that sensor on top of intake manifold does not solve this issue. Thanks!

[turbohugh]

vacuum leak ?

[ev1l335]

Originally Posted by turbohugh

vacuum leak ?

If it was a vacuum leak, how it would go away by applying throttle and holding RPM at fixed position? I would expect this issue to be permanent during idle if it was some kind of leak.

[ev1l335]

Originally Posted by E90 M335i

Check the sensor on top of the intake manifold and clean it. Had a similar issue on cold starts where it would start at 14.8 and dive close to 20 and the car stalls.

I did clean that sensor with Liqui Moly MAF cleaner, also sprayed Liqui Moly Electronic-Spray on connector pins, it did not help so far. I might replace that sensor if won't find any other possible causes that I can diagnose.

[BM3Rrrr]

Originally Posted by ev1l335

If it was a vacuum leak, how it would go away by applying throttle and holding RPM at fixed position? I would expect this issue to be permanent during idle if it was some kind of leak.

This isn't true, you can have a vacuum leak under idle and may not be present under load. It would be a very small leak somewhere but can affect the AFR's.
This is because vacuum leaks have less of a leaning effect on the fuel mixture as engine speed and load increase.

Have you replaced all your vacuum lines? I would start there as its cheap and easy to do. Alternatively you could do a smoke test but if the leak is small enough you may not see it.

Have you checked your spark plugs? Are they fouled at all?

[ev1l335]

Update about this issue - when I do unplug second map sensor (the one that is in manifold) issue completely disappears. I tried cleaning that sensor with maf cleaner, it does not help. Has anyone heard about those sensors failing? I don't want to buy new one to find out that issue is with something else. I also did change my tmap sensor and switched from 4 to 3.5 bar, this changed two things - cold start is no longer very harsh, car can stabilize itself when RPMs are high during warmup, hot start no longer stalls the car, idle is still rough but not as bad as it was with 4 bar tmap.

Regarding vacuum, I did check it while car was idling and I have 28,5 inHg when I connect to a nipple that is near oil filter, that value seems fine.

I also did replace all vacuum lines going from those nipples to wastegates (did this while was chasing other issue). Also I did remove RB external PCV valve from engine cover and throttle body. But none of that did not effect situation in any way.

[_N54]

Try replacing the sensor on the intake manifold if the issue completely disappeared when you unplugged it. To me that's a good indication that the sensor is not working and it's causing the car to do weird things when it's plugged in.

[m3an_f80]

SOrry to bring this back but have solved this problem?