BRM engine studder/shutter

[biggy238]

My 05.5 has been doing this really aggravating shutter that is directly tied to ~1800rpm, and top gear or top -1 (4th and fifth) and light throttle/engine load, cruising. This is the only condition it does this. My wife says she can't do it, but her driving style and gear choice are different.

The only precursor to this was when I was on the high plains, if I or cruise control went to light throttle to maintain speed downhill, when the fuel rate increased again after the downhill, the car would buck one time and then resume normal function.
I don't have vag-com so I'm blind ass far as diagnostics.
It sounds like something isn't right with the MAP but it has never generated a related code or CEL.

Any ideas?

From my Not-So-Smart phone

 

[JFettig]

Sounds like a typical BRM turbo stop screw problem.
TDIClub Forums
fancy tool for fixing it
TDIClub Forums

Only takes about 1/8-1/4 turn in on the stop screw, its best to use VCDS/Vag-com for proper adjustment.

 

[biggy238]

Thank you. Will look at this on the car when it stops raining.

From my Not-So-Smart phone

 

[biggy238]

Found something interesting today.
Those photos are the vac signal to the turbo (I believe) The line was connected in a way that had it twisted shut. I pulled it and corrected it. I test drove it with no improvement in function.
I then ran vac supply directly to n75 solenoid. That fixed the issue. The only time it lags now is with the AC on. I need to drive it farther to be certain, but so far its much improved.
With the increase in ambient temp, the car was almost unusable.

From my Not-So-Smart phone

 

[biggy238]

I also found this, the fresh air supply hose from the air box. I have no idea how long its been open. Looks like rodent damage.

From my Not-So-Smart phone