[tmwnzl]

Greetings from Germany

I'm posting a problem here that has been bothering me for some time. In the German E90 forums I did not get any results, maybe someone here has an idea.

I have an E90 330i built in 2005 with an N52B30AF engine (265,000km).
Whenever I give full throttle at low revs (under 1000 rpm) the engine chokes completely. For example, if I give full throttle in 5th gear at 900 rpm, it just jerks and doesn't build up any power. If I just stay on the pedal, it eventually manages over 1100 rpm and then it pulls up cleanly. Otherwise the car drives perfectly, even at medium or high revs and full throttle. There is no check engine light no matter how much I provoke the fault. Even when stationary, the engine chokes when I suddenly give full throttle.

I have already changed:

Vanos solenoid valve intake/exhaust original Bmw
6x ignition coils NGK
6x NGK spark plugs
6x fuel injectors (with less mileage)
DISA flap large
CCV
Oil filter cover with basket

I used a smoke device to check the intake for leaks, but everything is tight.

The VANOS test run from INPA runs smoothly. I used 'testO' to compare the target/actual values of Vanos intake/exhaust and the eccentric shaft and everything fits (otherwise I would have received an error code). I am now at a loss as to what the problem could be.
When I put the engine into emergency mode, the error does not occur. The lambda value is just under 3 during jerking, as soon as it pulls up cleanly it goes to 1 as it should. I wonder why the engine control unit does not throw an error.

I have recorded 2 videos here. On one you can see the lag when stationary at full throttle. On the second one you can see how the car jerks a lot in first gear at full throttle. I'll make another video in which you can see how the car jerks very strongly at full throttle in a high gear below 1000 rpm without a break.

https://www.veed.io/view/464f198b-4f...ue&panel=share

https://www.veed.io/view/9e95c636-4c...ue&panel=share

Thanks for the Help

[PhaceN52]

Try to run the engine with the maf disconnected... Is the car sluggish when accelerating normally from a stop? Seems like lambda > 1 means too much oxygen, ruled out fuel pump?

[tmwnzl]

@PhaceN52 This version of the N52 does not have a maf sensor. Only one inlet temperature sensor is installed. The air mass is calculated from the throttle valve angle and the intake manifold pressure sensor.

During normal acceleration without full throttle the car runs perfectly - the error occurs as soon as you exceed a certain point when accelerating (but only below ~1200 rpm, above that I can always give full throttle).

I have looked at the injection times of the fuel valves - these are limited to about 7ms during jerking, as soon as it is out of jerking or I give a little less gas and it can accelerate it sometimes opens up to 15ms - so it looks like the engine control unit is limiting the amount of fuel but unfortunately I can't find out why. I have tested all the sensors electronically and checked the values for plausibility.

[Tambohamilton]

Sounds like there's a hole in the map in the DME. Have you tried updating/reflashing the DME? Or maybe reset adaptations?

[ptpending]

Originally Posted by tmwnzl

@PhaceN52 This version of the N52 does not have a maf sensor. Only one inlet temperature sensor is installed. The air mass is calculated from the throttle valve angle and the intake manifold pressure sensor.

During normal acceleration without full throttle the car runs perfectly - the error occurs as soon as you exceed a certain point when accelerating (but only below ~1200 rpm, above that I can always give full throttle).

I have looked at the injection times of the fuel valves - these are limited to about 7ms during jerking, as soon as it is out of jerking or I give a little less gas and it can accelerate it sometimes opens up to 15ms - so it looks like the engine control unit is limiting the amount of fuel but unfortunately I can't find out why. I have tested all the sensors electronically and checked the values for plausibility.

it is very strange to hear that there is not MAF here because from what i've got from technical info, after engine warm-up it goes to valvetronic mode and do not use throttle at all, it is opened.
also i've checked the TIS diagrams, and for MSV70 N52 engines, (i suppose that your 2005 MY version is running with MSV70) the air-mass sensor is shown on diagrams, while for MSV80 versions there can be HFM or sometimes only air temp sensor.

[tmwnzl]

Originally Posted by ptpending

it is very strange to hear that there is not MAF here because from what i've got from technical info, after engine warm-up it goes to valvetronic mode and do not use throttle at all, it is opened.
also i've checked the TIS diagrams, and for MSV70 N52 engines, (i suppose that your 2005 MY version is running with MSV70) the air-mass sensor is shown on diagrams, while for MSV80 versions there can be HFM or sometimes only air temp sensor.

Yes you are correct after a short warmup period it goes into UGD Mode where the air mass is controlled by the valve lift. The throttle is still in use sometimes its not fully opened all the time.

My N52 also runs with the MSV70 - but with the version without MAF. I also looked at the diagrams in TIS as I didn't know that there was a version without MAF. Unfortunately, the TIS only contains diagrams for the version with MAF. I then used the chassis number to find out which sensor is installed in the intake and it only showed a temperature sensor, which is also installed in my vehicle. So everything seems correct.

Originally Posted by Tambohamilton

Sounds like there's a hole in the map in the DME. Have you tried updating/reflashing the DME? Or maybe reset adaptations?

So far I have only reset all adaptations because I don't have the right equipment for a DME Flash (power supply > 100A)

[ptpending]

Originally Posted by tmwnzl

Yes you are correct after a short warmup period it goes into UGD Mode where the air mass is controlled by the valve lift. The throttle is still in use sometimes its not fully opened all the time.

My N52 also runs with the MSV70 - but with the version without MAF. I also looked at the diagrams in TIS as I didn't know that there was a version without MAF. Unfortunately, the TIS only contains diagrams for the version with MAF. I then used the chassis number to find out which sensor is installed in the intake and it only showed a temperature sensor, which is also installed in my vehicle. So everything seems correct.



So far I have only reset all adaptations because I don't have the right equipment for a DME Flash (power supply > 100A)

ok, i found in ETK that for EU-made 330i N52 and for N52N there was air temp sensor for countries with good fuel and HFM for countries with not so good fuel.
But for mine 130i in ETK only HFM is in the list.

[Tambohamilton]

Originally Posted by tmwnzl

So far I have only reset all adaptations because I don't have the right equipment for a DME Flash (power supply > 100A)

Personally I wouldn't worry too much about that. So long as your battery is decent it would be fine with nothing, or you could plug in a decent charger to help. But don't take my word for it better safe than sorry.

[tmwnzl]

I have recorded 2 videos here. On one you can see the lag when stationary at full throttle. On the second one you can see how the car jerks a lot in first gear at full throttle. I'll make another video in which you can see how the car jerks very strongly at full throttle in a high gear below 1000 rpm without a break.

https://www.veed.io/view/464f198b-4f...ue&panel=share

https://www.veed.io/view/9e95c636-4c...ue&panel=share

Originally Posted by Tambohamilton

Personally I wouldn't worry too much about that. So long as your battery is decent it would be fine with nothing, or you could plug in a decent charger to help. But don't take my word for it better safe than sorry.

I'll get myself a good charger and flash the control unit. But I can't explain how something like this can happen, the fault has existed for about 1 year and I've had the car for 2 1/2 years.

[Tambohamilton]

Yeah, I agree - it shouldn't just happen. To be honest, I'm only suggesting it because I don't have a better idea. You need a hint, because everything else checks fine... Maybe by changing/resetting the software the behaviour will change, and that will give you a lead. Or maybe it'll fix it - seems unlikely, but fingers crossed!

[tmwnzl]

Update: The error has been fixed. I'm sharing the solution to my problem here. It was actually the small DiSa flap. This could no longer be closed completely, which probably led to problems with the air supply in the lower speed range. From the outside, the flaps looked flawless - no wobbling or other damage. I then removed it again and activated it and realised that the small one wasn't closing completely. I have now fitted a new one and deleted all the adaptations and the car is running smoothly again.



I took the flap apart - it is full of oil as the car was probably driven for a long time with a defective KGE until I got it. The oil then got into the housing through the bearing of the flap. I couldn't find any mechanical defects in the gearing.

[ptpending]

the main problem for you will be to glue this case back
because many glues do not tolerate the high engine temperatures and become soft and not protecting internals

[The Nightman]

Originally Posted by tmwnzl

Update: The error has been fixed. I'm sharing the solution to my problem here. It was actually the small DiSa flap. This could no longer be closed completely, which probably led to problems with the air supply in the lower speed range. From the outside, the flaps looked flawless - no wobbling or other damage. I then removed it again and activated it and realised that the small one wasn't closing completely. I have now fitted a new one and deleted all the adaptations and the car is running smoothly again.



I took the flap apart - it is full of oil as the car was probably driven for a long time with a defective KGE until I got it. The oil then got into the housing through the bearing of the flap. I couldn't find any mechanical defects in the gearing.

Thanks for the update. I had to deal with oil filled DISA valves as well. A good excuse to run an oil catch can to help reduce the amount of oil in the intake manifold

https://www.e90post.com/forums/showthread.php?t=1748288

[Tambohamilton]

Originally Posted by ptpending

the main problem for you will be to glue this case back
because many glues do not tolerate the high engine temperatures and become soft and not protecting internals

He replaced it

[kolopn]

Basically to avoid having oil in disa, just replace shaft seal - 10x14x3mm

[Suvorovo]

This is a cool kit, I've seen people use some kind of acid to melt the unit together.

https://vanos-bmw.com/product/repair...n52t-n51-small