Yes, actually even "better" than on mine having renewed the timing belt three months ago, and definitely not the culprit for lumpy running.
Perhaps could try what a forced DPF regeneration while driving would do? But would like to make a recordings "before and after" to see if it improves the situation. Let me know so can prepare a dataset for VCDS.
Correct, VW techs also have a database of possibly similar symptoms.
The injector 4 is something to check anyway. A possibility to further diagnose would be to swap injector 4 with another one (perhaps with cylinder 1, because of firing order 1-3-4-2) and check if the suspect location follows. However, not sure if swapping makes economically sense.
Meanwhile, perhaps you could redo a cold lumpy startup (same as LOG-02) at least once more - just to build confidence the measurement data we saw about "IDE09330 Cylinder 4 bank 1 internal moment" sticks with cylinder 4.
I agree with the theory - it's just a challenge to pinpoint the culprit because ECU indeed tries to compensate possibly one being partially out. Also the flywheel mass itself resists speed changes, and finally dual mass pendulums swinging back and forth probably even further blur what we see in the data
Anyways, I do appreciate you collecting and sharing the data - I'm hoping we eventually can conclude a method to pinpoint where the issue is - possibly the internal moment calculated by ECU is the key.
The parameter "Fuel injection time deviation:" have been tried to use to pinpoint possibly a faulty injector - but not successfully - I think. Anyways, below the plots for the earlier logs: LOG-02 (lumpy), LOG-04 (smooth).
In LOG-04 the cylinder 4 curve is suspiciously "too flat" - perhaps it's at the limit of it's allowed adjustment range.
Also below the calculated deviations based on "IN_Injection_speed_injector". Although also these seem to point the same cylinder I'm trying to understand the justification for this
