Rußbegrenzung ab 3000 U/min | Posts 16+

Hello!

Today, I lowered the target value for air mass to 770 mg/H, and surprisingly, the soot limit (allowed injection amount) didn't change compared to before!

I don't think the problem is related to the mass airflow sensor.
I read something again and found this:

-> Air mass limitation (Russ limitation): The maximum fuel injection quantity that can currently be combusted while complying with emission regulations. It is calculated, among other things, based on the mass airflow sensor (MAF) signal, which in turn depends on factors such as the boost pressure, the intake air temperature, the engine speed, and the condition of the MAF sensor.

Hmm, it could also be, for example, the sensor for the intake air temperature!

Vieleicht ist es auch normal beim AFN das die Einspritzmenge ab 3000 U/min so allmählich zurückgeregelt wird ! Wäre mal interressant ein Logfile von einem anderen AFN zu sehen ! Die maximale Einspritzmenge geht auch nie über 42 mg/H ! Ist Is that okay?
And is the boost pressure okay at 1950 mbar?

'Does anyone here have an AFN (Application Feature Number) or a log file from group 8 that shows that the torque limitation is the lowest value?'

Regarding the target value for the air mass, which I set to 770 mg/H via adaptation, is it only used for the EGR control, or does it also serve as a target value for soot reduction? Because if it were only for the EGR control, it would be clear that the soot reduction system in my car is still always operating at its lowest level, given my low actual air mass readings.

Thank you in advance for your efforts.

Best regards, Raik.

Gunman wrote:

Regarding the target value for the air mass, which I set to 770 mg/H via adaptation, is it only used for the EGR control, or also as a target value for soot reduction? Because if it were only for the EGR, then it's clear that the soot reduction system in my car is still showing the lowest value!

AFAIK, that's exactly how it works because the soot limit is based on the actual LM (lambda) value, not the target value.

Under what operating conditions did you measure and adjust the 770 mg? Adjustment is always only applied to the target value = Field 2!

Yes, that's right. I adjusted the target value, but I actually thought that if the actual value is greater than the target value, the full injection amount would be released.
That's probably not the case, though!
Besides, there are other parameters that affect soot formation, such as the intake air temperature!

Best regards, Raik.

Gunman wrote:

Unless there are other parameters that affect the soot limit. act like, for example, the intake air temperature!

Initially, yes, but ultimately they all contribute to the LMM value, which (along with the engine speed) is the primary factor influencing soot reduction.

So, I should probably try the diode trick first! Does that work with Bosch mass airflow sensors too? Or not? Assuming my engine control unit doesn't detect anything. Year of manufacture: 1998.

Best regards, Raik.