I never like to start a thread and leave it hanging. I always try to follow up and close it out, assuming I ever get the problem resolved. In this case, there seems to be very positive results from what I've done so far, the biggest of which is the lack of overheating on the highway. At 75mph with the A/C running, the coolant temperature routinely hovered around 100-105˚C. No telling what the EGT's were doing to my turbo or head... Post tuning, I haven't seen anything over 100˚ while climbing a long, steep hill and temperature dropped back to 85˚ in under a minute. Highway temps seem to be in the 80-85˚ range now, definitely a significant improvement and very telling about how overfuelled the engine was before.
I drove the car last night around 10 PM so it was very dark. Had a modern Lexus behind me with the HID headlights so I took advantage of the opportunity to check for smoke. Only smoke I got was with foot hard down right at the upshift I got a little "poot" and that was it. Very satisfying not to have my own chemical fog following me around anymore.
The ALDA resealing idea came from this thread:
OM602 ALDA o ring size If you get on Youtube and search for the ALDA O-ring, you'll find a Dieselmeken video on how to do the shaft seal. He doesn't mention the perimeter seal. I did the shaft seal and still had leaking. Dumped the ALDA in a bucket of water and attached a hose and blew and found the perimeter seal leaking on all 4 sides. Installing a fresh O-ring seal for the perimeter seal made the ALDA gas tight, even holds a vacuum now. With it working as designed, the engine can be tuned lean and still make plenty of power. I suspect all of the ALDA adjustments people make on their cars is to compensate for seals leaking and not functioning properly. Smoke ≠ Power.