Problem with W204 RPM Fluctuations

[B0bby92]

I replaced the O2 sensor today but this error keeps coming back. What should I do? Please help!

 

[B0bby92]

I would like to note that the fault may also be in the torque converter clutch bypass valve - it stalls. Diagnostics does not reveal this defect. Again, this can be found out from the actual values - consumed and actual current (A) for a given valve. Again, the test can be performed by disabling (Xentry) the inverter bypass clutch. Applies to gearbox (722.6).

I don't have this option on (722.640).

 

[blueabyss]

Load it in DAS as prototypes (you must have an old version of diagnostics, ideally 10.2008 or modified DAS prototypes).
The rest is according to the screenshots.
I don't know if Xentry has such a feature.

 

[blueabyss]

Reset the average quantity adaptation data after replacing the following components: G3/2 O2 sensor, broadband lambda probe for diesel engines. This relatively expensive part is not installed in diesel engines for no reason. It plays an important role in controlling exhaust emissions and ensuring proper DPF regeneration. Lambda (excess air in the exhaust) value information is very important for engine operation and has literally existential significance for the engine and exhaust system.
Almost everything in your car is disconnected, so I would probably also disconnect the lambda probe by software

 

[B0bby92]

Reset the average quantity adaptation data after replacing the following components: G3/2 O2 sensor, broadband lambda probe for diesel engines. This relatively expensive part is not installed in diesel engines for no reason. It plays an important role in controlling exhaust emissions and ensuring proper DPF regeneration. Lambda (excess air in the exhaust) value information is very important for engine operation and has literally existential significance for the engine and exhaust system.
Almost everything in your car is disconnected, so I would probably also disconnect the lambda probe by software

Are you sure about this, buddy? Doesn't the O2 sensor control the injector quantity?

 

[blueabyss]

I don't think this is dogma, but my measurements also prove that the role of the oxygen sensor in diesel engines is not to regulate the amount of fuel mixed with air (as is the case with gasoline engines).
The main role of the lambda probe in diesel engines is to regulate the ratio of recirculated flue gases and air, as well as to dose fuel during the regeneration stage of any filter when burning soot (your system is free of these components)!
The main role of the lambda probe in diesel engines is to correct the mixture to the Lambda 1 value so that the mixture is combustible (stoichiometric ratio).
At full load, it ensures that the mixture is not too lean (high in nitrogen oxides).
Provides a constant sufficient excess of air (oxidation, reduction of soot formation).
However, this applies if the EGR system is operating and regenerations are occurring.
Since your engine's emissions system is completely removed, I think lambda control is completely wrong and unnecessary here.
Take my statement as a purely theoretical version - I have not tested anything like this, since I do not do such repairs or modifications to vehicles.
I don't think I can replace hundreds of engineers and designers while improving the system by removing components. You modified the engine for the turn of the 90s. At that time, there was no lambda probe on diesel engines - it was not needed due to the peculiarities of the exhaust system.

 

[B0bby92]

In Xentry when I do "Reset values of quantity mean value adaptation". It says: Do this if you have replaced: MAF sensor, fuel injector or O2 sensor. And that makes me think that O2 sensor plays a role in fuel quantity adaptation and performance

 

[blueabyss]

I don't want to refute your point, but I know what the individual components do and how they depend on each other. Tuning these components is more or less changing the tuning data in the ECU.

All this training is carried out only with the ignition on, and not with the engine running.

For diesel fuel, a wideband lambda probe is used because diesel fuel has a much greater variability in air/fuel ratio.
It's more about combustion control and smoke control than constantly trying to achieve lambda 1 (stoichiometric) as with gasoline.
At high loads, diesel fuel, like gasoline, ignores lambda, open circuit and uses "maps" to deliver fuel (in combination with many other parameters).
After what you have done to the engine, its intake and exhaust, the lambda probe is practically useless.

 

[B0bby92]

Load it in DAS as prototypes (you must have an old version of diagnostics, ideally 10.2008 or modified DAS prototypes).
The rest is according to the screenshots.
I don't know if Xentry has such a feature.

Where can I find this DAS 10.2008 for download? Does it work with Openport 2.0 J2534?

 

[blueabyss]

Try this solution, it works.

Add W204 in DAS

Here is a set of files (I created myself a few years ago) that you need to add to your folders...

https://autogmt.com