Injection amount exceeds smoke reduction limit

Hello!

Yesterday, I successfully installed and started using Ulf's 2.4 adapter for the first time. My ATD, with a power output of 74kW, often exhibits weak acceleration, and the workshops have not yet found any issues.

The only value that was noticeably out of range at 3000 RPM was the fuel injection amount for smoke reduction, which was approximately 44 mg/H instead of the expected 16..36. The air mass is 930 mg/H, which is within the tolerance range, but closer to the lower limit. Does this indicate a dirty mass airflow sensor?

Can we infer anything (especially from the fuel injection amount)? Yesterday, during the test drive, I had the impression that I caught a 'vital' phase of the engine (as always, the pain also goes away at the dentist's). Perhaps the readings will be more informative next time, when the engine is running slower again!

Thank you for your comments!
Best regards.
Ralf.

Hello Ralf,

What were the other values in that ad group?

Hello Michael II!

The values for ad group 8:

Speed: 3024.
EM Driver Preference: 48.3
EM Torque Limit: 41.5
EM smoke reduction: 44.5


What exactly do these three values indicate? How are these values calculated?

LG
Ralf.

Ralfonso wrote:

EM Driver Preference: 48.3 EM Torque Limit: 41.5 EM smoke reduction: 44.5 What exactly do these three values indicate? How are these values calculated?

Hi Ralf,

Driver request = accelerator pedal position, translated into fuel injection amount.

Smoke limitation = currently the highest possible injection amount without exceeding the permissible soot emissions. It is mainly calculated based on the air-fuel ratio (AFR) and engine speed.

Torque limiting = absolute limitation to prevent overload for the entire powertrain. Firmly programmed and the "natural enemy" of the desire for more power.

The actual injection amount is determined by the currently lowest limit.
If the smoke limit is being reached even with the engine running at full throttle, there's often something wrong with the mass airflow sensor (MAF) or the intake system.

Hello Ulf!

Thank you for the good explanation! Since, in my case, the smoke limit is not the determining factor, I assume that the occasional lack of draft is not caused by that. Do you have any other suggestions regarding which parameters I should pay particular attention to concerning this problem? During the last test run, the power output was functioning correctly, so all the values were within the specified tolerances.

Thank you in advance for your information!
Ralf.

Ralfonso wrote:

Do you have any other advice on which parameters I should pay particular attention to regarding this problem?

Hi Ralf,

"I can't provide any specific additional parameters, but I can share the technical article on troubleshooting with VAGCOM."
Even though it wasn't specifically written for PDs, much of it can be applied.