Fixed!!! Hallelujah!
My limp mode has disappeared!
And as we were pretty sure of by now, it was the stuck wastegate. The problem was then getting it unstuck.
When I was under the car last week, I was trying various ways to stick something up in there against the wastegate lever and managed to get a stick against it and decent whack or two via a hammer on the other end. I THOUGHT, but couldn't be at all sure, I saw it move slightly. But additional attempts to move it failed.
Thursday had an opportunity to stomp it in 3rd gear once or twice and it ran all the way up to 4000 RPM and didn't drop into limp mode from the overboost. I was rather amazed and could only conclude that I must have gotten it slightly open and it was bypassing just enough exhaust to limit the boost to below the threshold that causes limp mode.
Just got back this afternoon from an overnight trip where I had quite a few on-ramp and other uphill opportunities to stomp it in 3rd all the way to 4000 rpm and could never get it to cut back the power. Even ran it to 3500 in 4th gear (as fast as I wanted to go!). Wow! Problem GONE!
Got home, unloaded the family and luggage and put it back on the ramps and let it cool over supper. Pried on the actuator rod a little again with pliers and didn't seem any better so I figured it was still stuck, but just open slightly. So it was time to try what had been suggested lubricant and bike pump trick and now I had time. Shot some WD-40 into the actuator (had to make a double-length "straw" to reach far enough and bend the end to aim it in along the actuator rod - both accomplished with strategic use of electrical tape).
Got out the bike pump kit I got at Lowes on the suggestion of Philh (see thread
http://forums.tdiclub.com/showthread.php?t=167981) which solved the problem of actually connecting a bike pump to the actuator hose. I would've tried that last time but couldn't figure a good way to hook up the pump. Pulled the actuator hose off the N75 valve and dropped it down behind the engine. Crawled back under, hooked up the bike pump and sure enough the actuator opened the wastegate!!! Yeeee Haah! (there's no emoticon for wildly dancing for joy around the garage). Seemed like it took a lot of pressure at first to move it, but don't think it ever really went over 40 psi (fortunately my pump has a gauge on it). So I exercised it quite a bit and it seemed to move a little more easily, but still takes 30 psi for full deflection. I hadn't realized until now that it's working against a return spring. Seems to take about 10 psi to begin to move, 20 to get halfway open and 30 for full travel.
I also know that the tubing is good because the gate would stay open until I released the pump's clamp from the adapter and let the air bleed back out.
Then after all that, I finally found an easy way to pry the wastegate lever. Stuck the long end of a large framers square up against the pin that the actuator rod hooks to. Pry against the oil line (which is sturdy) and moderate pressure easily opened the gate. But you can feel the return spring in the actuator is pretty stiff, so as it turns out you can't easily move the rod with long pliers anyhow. Gotta use a long pry lever. But the pry method is a quick check for stuckness and then the bike pump will verify proper air operation.
SO! We finally we got her figured out and fixed and I didn't even have to pull the turbo. My profuse thanks to EVERYONE that has replied to help me sort it all out. Not only did we fix the problem, but got the intake cleaned too (which eliminated smoke), as well as new filters and also learned that my injector nozzles are very due for replacement. Although I'd rather not have had to deal with the problem, I've learned a ton about how all the systems work and where everything is located under the hood.
A set of .205mm arrived yesterday and Turbinewhine has graciously offered his time and expertise in a few weeks to ensure the process goes smoothly. After that, hopefully she's good for another 220k miles!
Mark
