Wastegate, boost control valve

Hello TDI enthusiasts,
I have a 1993 B4 in which I installed a complete 1994 engine last year due to a turbocharger defect.
The '94 engine has a slightly smaller turbocharger with a modified wastegate.
After adjusting the hoses to the cooling system and replacing the front pipe, everything worked.
Unfortunately, the wastegate actuator rod was slightly bent, so I had to straighten it and adjust it, more or less by guesswork.
Can someone provide me with the exact settings for the linkage?
Since the renovation, I've been experiencing noticeable fluctuations in performance at engine speeds above 3000 RPM.
If I disconnect the plug from the turbocharger control valve, the problem disappears, but the overall performance decreases significantly.
The NHG has already been replaced, and the LMM is also working correctly. I've ordered a new control valve just in case.
Does anyone have any other ideas about what I should do?

Thank you very much.

Markus.

Hello Markus,

With a diagnostic system, you should be able to properly adjust your wastegate.
Given that there may be communication problems with your engine control unit (based on experiences from the forum), please search for "1Z adapter" using the AND operator. Tip: Start baud rate 240.
If communication is established, the first thing you should do is read the error codes, as the problem might be caused by something else.
Then, examine the measured values for boost pressure and the duty cycle of the magnetic valve used for boost pressure regulation, and compare them to the target values.
It should be measurement block 10 or 11, but both the measurement block and the target values are described in one of Michael's technical articles.
If you change the actuation rod of your wastegate, this must be reflected in the specified duty cycle.

Theoretically, you should be able to achieve the same result using a multimeter (better multimeters can measure duty cycles, but even an analog multimeter can be used to measure the voltage at the solenoid valve), but if you have other issues with the motor, this won't lead to a satisfactory result.

Best regards, Rainer.

Hello Rainer,
Thank you for the tips.
After removing the wastegate again and carefully examining the threads, I found the original color marking on the locking nut of the base setting.
I adjusted the part like that and reinstalled it.
However, the issue with the wave-like acceleration only disappeared after I replaced the boost pressure control valve.
Now the engine is running smoothly and without any problems.
And all this hassle and searching for just 30 euros...
Best regards,

Markus.

markus_b4tdi wrote:

Now the engine is running smoothly and without any problems. And all this trouble and searching for 30 euros....

Hi Markus,

Be happy about the ridiculously small financial damage - most other TDI drivers would have gone to (or multiple) workshops and would have lost at least three-digit amounts of money .