[10E92335]

This is gonna be a post two months in the making trying to scour forums for information to no avail trying to fix my completely bone stock 2010 N54 335i. I'm gonna list everything i know about my car right now Any help would be hugely appreciated! hoping someone in here knows a whole lot more than i do.

Symptoms are as follows:
No Long Cranks ---> Starts to extreme rough idle jumping around 1200RPM---> Only slight rough idle once closed loop (very minor shakes every second or so increasing frequency with the amount of RPMs) ---> hard to hold RPMs stable (drops slightly over time even with the same throttle input) ---> Burble with stock exhaust as RPMs drop (may be normal IDK)

What i know:

- Bank 1+2 LTFTs 25-30% at idle, starts at 20-25 slight increase with throttle to a max of 30
- Bank 1+2 STFTs close to 0 at idle but increase greatly with throttle but drop to 8-10% holding at same RPMs
- 02 sensor values in normal ranges of each other and act with normal behaviour in response to throttle
- Normal LPFP and HPFP values
- Extreme Rough Idle in open loop and only slightly rough once in closed loop
- Spark plugs (Brand New) blackened after less than 20km (although car doesnt move from driveway and idles mostly)
- Spark plugs pulled and completely dry

Things already done

- PCV Valve replaced
- 6x Ignition Coils (Eldor)
- 6x Spark Plugs (OEM Bosch)
- Vanos Solenoids Cleaned
- Both MAP sensors "Cleaned" (Intake Manifold Sensor black even after cleaning in which it was covered in gunk)

Thankyou for your time and Thankyou for your help in advance

[suspect]

Originally Posted by 10E92335

This is gonna be a post two months in the making trying to scour forums for information to no avail trying to fix my completely bone stock 2010 N54 335i. I'm gonna list everything i know about my car right now Any help would be hugely appreciated! hoping someone in here knows a whole lot more than i do.

Symptoms are as follows:
No Long Cranks ---> Starts to extreme rough idle jumping around 1200RPM---> Only slight rough idle once closed loop (very minor shakes every second or so increasing frequency with the amount of RPMs) ---> hard to hold RPMs stable (drops slightly over time even with the same throttle input) ---> Burble with stock exhaust as RPMs drop (may be normal IDK)

What i know:

- Bank 1+2 LTFTs 25-30% at idle, starts at 20-25 slight increase with throttle to a max of 30
- Bank 1+2 STFTs close to 0 at idle but increase greatly with throttle but drop to 8-10% holding at same RPMs
- 02 sensor values in normal ranges of each other and act with normal behaviour in response to throttle
- Normal LPFP and HPFP values
- Extreme Rough Idle in open loop and only slightly rough once in closed loop
- Spark plugs (Brand New) blackened after less than 20km (although car doesnt move from driveway and idles mostly)
- Spark plugs pulled and completely dry

Things already done

- PCV Valve replaced
- 6x Ignition Coils (Eldor)
- 6x Spark Plugs (OEM Bosch)
- Vanos Solenoids Cleaned
- Both MAP sensors "Cleaned" (Intake Manifold Sensor black even after cleaning in which it was covered in gunk)

Thankyou for your time and Thankyou for your help in advance

What values are you getting for your AFR, HPFP and LPFP? Log would help. How are you checking these values?

[10E92335]

Originally Posted by suspect

What values are you getting for your AFR, HPFP and LPFP? Log would help. How are you checking these values?

I only have access to INPA (K+DCAN cable) and a handheld OBD BMW reader at the moment so I am unable to see AFR. Values for LPFP at idle around 69-72psi and 695-720psi for the HPFP. I may have to buy MHD at some point so i am able to log values for you to see

[OMEGA412]

30% ltft is very high. That would indicate you are running lean and your dme is compensating by adding extra fuel. What index are your injectors? And have you tried reseting all fueling related adaptations?

[10E92335]

Originally Posted by OMEGA412

30% ltft is very high. That would indicate you are running lean and your dme is compensating by adding extra fuel. What index are your injectors? And have you tried reseting all fueling related adaptations?

Yeah i tried resetting all adaptations but it didn’t change the rough idle from startup and minor hiccups in closed loop at all. The injectors are a mix of Index 5,7,8 which i know isn’t ideal although i suspected it would be unlikely a clogged injector is causing huge fuel trims across both banks

[OMEGA412]

Originally Posted by 10E92335

Yeah i tried resetting all adaptations but it didn’t change the rough idle from startup and minor hiccups in closed loop at all. The injectors are a mix of Index 5,7,8 which i know isn’t ideal although i suspected it would be unlikely a clogged injector is causing huge fuel trims across both banks

Are you sure they were coded to the car? If heard of shifty shops installing new injectors and not coding them. But if your hfpf and lpfp psis are good I'd say injectors.

[10E92335]

Originally Posted by OMEGA412

Are you sure they were coded to the car? If heard of shifty shops installing new injectors and not coding them. But if your hfpf and lpfp psis are good I'd say injectors.

I can definitely pull all the injectors and code them up as i have a new set of injector seals when they go back in so i'll probably give that a go. Do you think the lean running could be caused by excess air in the system or do you think the other things show that that's not possible?

UPDATE: Could read codes without pulling injectors and checked them using INPA and they were already coded perfectly :/

[Bannockburn]

Have you checked for any vacuum leaks in the intake system that could potentially cause a lean condition, considering the high LTFT values?

[marv85]

I had a similar problem but the idle wasn't as rough as you describe. I had just swapped over to MSD81, and it turned out to be a bad DME. Swapped to yet another MSD81 and my fueling issues were gone.

In my case, debug was easy because swapping back to MSD80 recovers the car so it pointed at DME/programming as the problem.

Did this problem pop up all of a sudden for you?

[10E92335]

Originally Posted by marv85

I had a similar problem but the idle wasn't as rough as you describe. I had just swapped over to MSD81, and it turned out to be a bad DME. Swapped to yet another MSD81 and my fueling issues were gone.

In my case, debug was easy because swapping back to MSD80 recovers the car so it pointed at DME/programming as the problem.

Did this problem pop up all of a sudden for you?

Oh really thats interesting, did you have any codes when this was happening and was the car running the stock map? if a smoke test doesnt show any results ill try and get my hands on another DME - i bought the car like this, the start is rough but when closed loop idling the roughness would be pretty unnoticeable to the average person.