Strange Load Behavior!

I built a Garrett VNT17 turbocharger for my Audi A4 (AFN engine).

Since then, I've been experiencing a problem where the boost pressure regulates to 1.35 bar at full throttle and engine speeds above 3500 RPM.

In addition to that, the engine itself, even without any load, is still subjected to boost pressure!

At 3000 RPM with approximately 0.2 bar, and already at 0.4 bar above 4000 RPM!

Therefore, I think the VTG rod is probably too short, and the guide vanes can never be set to the '0' position!

Now I wanted to turn the VTG shaft for a longer length! With a longitudinally mounted engine, this isn't so easy because everything is very tightly packed in there!

Once I've released the two vacuum-holding cups, can I remove the container? Or do I need to twist the container out of the 'second VTG rod' using the 'first VTG rod'?

It would be really helpful if someone could give me a more detailed description. I don't want to break anything with my clumsy hands!

Okay, here's the translation:

Thank you.

Manuel.

Hello,

If there's no emergency boost at 1.35 bar, then either your boost gauge is broken, you have a pressure leak on the way to the boost sensor, or the target boost pressure in your ECU is set very high. It's also possible that the emergency program in your ECU is not working correctly, who knows.

You can determine if the VTG rod is too short by observing the duty cycle of the magnetic valve used for turbocharger boost pressure control.
I'm not quite clear why you had a larger turbocharger installed if you didn't understand the function of the previous boost control system.

Best regards, Rainer.