Dynamically check and, if necessary, adjust the start of injection

Dear diesel specialists!

Although my A4 (10/96, AFN, 81 kW, 131,000 km, no tuning!) runs and starts perfectly, I would like to check the injection timing using my (regularly licensed) VAG-COM 311.2.
I personally performed the last timing belt replacement (including all associated components, at approximately 94,000 km), and at that time, I had the injection timing electronically checked by a Volkswagen dealer ('Everything was perfectly fine').

Now, to my problem:
When I check the EDC using VAGCOM at idle with a warm engine (group 000, then 'Go'), I see a value of '054' in block 2 and a value of '152' in block 9. This seems to be working correctly!
When I then go to 'Basic Settings' (and only then does the TDI timing checker appear correctly), the engine runs more roughly, and block 2 shows a reading of (001..003). In the diagram, only the yellow points appear at the bottom edge, with the message 'Timing is too advanced to be plotted.'
It seems like there's something wrong with the fuel injection timing!

Here are my questions about that:
'Could the injection timing have shifted over the course of the 41,000 km (as I said, the engine is still running great), or did the people at Volkswagen read the values in the wrong (regulated) mode back then?'
2.) What happens if I adjust the fuel injection timing correctly (resulting in a changed start or response behavior)? Surely, VW had a reason for this default setting!
3.) Or should I just leave it alone (never touch a running system)?
4.) In the TDI timing checker, where is the setting for 'Early' (which seems to correspond to 'advanced,' approximately 0-30?) and 'Late' (approximately 90-100?)?

I have also read the excellent technical article 'Testing and Adjusting the 1.9 Liter TDI VE-ESP'. I think I understood part of it , but I couldn't find an answer to the questions above!
Bei der Einstellung des Einspritzbeginns stellt man den 'mechanischen' Arbeitspunkt des ganzen Systems ein. Dazu wird der Spritzversteller (Stellglied der Regelung) 'an die Kante' (= Spät, Ventil für Einspritzbeginn wird dauernd angesteuert) gefahren, um später der eigentlichen Regelung einen möglichst großen Bereich zu bieten. RichI don't understand. Can you please rephrase your question?

Thank you in advance!

Hi,

Quote:

Bei der Einstellung des Einspritzbeginns stellt man den "mechanischen" Arbeitspunkt des ganzen Systems ein. Dazu wird der Spritzversteller (Stellglied der Regelung) "an die Kante" (= Spät, Ventil für Einspritzbeginn wird dauernd angesteuert) gefahren, um später der eigentlichen Regelung einen möglichst großen Bereich zu bieten. Richtig?????

Okay. Could it be that you've mixed up the "basic settings mode" and the "non-basic settings mode"?

Default setting mode = maximum delayed start time = essentially quieter operation.
If you are a customer of mine, you can also download the German versions of the plugins from your account, which will contain all the text in German.

Best regards, Rainer.

Hi Rainer,

You seem to be always online... ..
Thank you for the quick response.
As soon as I am in the basic settings mode (where the TDI Timing Checker appears), the engine running changes. I can't say for sure that it runs quieter!

Do I have any advantages if I adjust the settings? (Longer engine life, lower fuel consumption, better acceleration, or even a six-pack for the driver ???)

Is my pump timing too early or too late? I'm just asking to avoid a trial and error process, which, according to Murphy's Law, always seems to go in the wrong direction.

Best regards, Cashier.

Hi,

too advanced = too early.

In the 'Result' field, you can see the current status, which will tell you in which direction you need to turn.
Advantages: quieter operation, improved starting behavior. If the settings are too far off, the emergency program will activate to prevent damage. However, if you are satisfied with your current settings...

In the image below, you can see the current plugin from the shop that is included with VAG-COM. The setting on my AHF isn't perfect either (a little too late), but it's within the acceptable range.

Best regards, Rainer.