I have a 2003 Jetta TDI w/ 118K. Lost the first turbo under warranty @ 40K (2005). The second lasted another three years before it presented the current problem.
When I start the car from any engine off condition the turbo will not engage until I bring the engine up 2800 RPM. From that point on it runs great until I shut down the engine. The time that the engine has been shut down, seconds or days, does not affect the condition nor does the temperature of the engine. Almost got killed when I pulled out into traffic forgetting that I would have no acceleration for the 20 odd seconds it takes for the turbo to engage. Time to find and fix the problem.
Having reviewed the turbo section in the FAQ, I plan to remove and test the actuator, but I would think that a bad actuator or turbo would continue to cause problems after the initial run up to 2800 RPM. But it runs great so long as I don't shut it off.
Ideas?