Thank you for the detailed info Andy! I have indeed taken the turbo apart (it took copious time, penetrating oil, heat and banging to get it separated) and am cleaning and reassembling it today. The vanes were pretty clean actually so I'm not holding out much hope there, but, the vnt actuator sounds like a baby's rattle, so maybe even though its functioning ok it is having intermittent failures due to rust inside.
If this post is too long, here are links to VCSD logs for the MAF and turbo. 3rd gear, WOT:
https://docs.google.com/spreadsheet...3tLyTSPkGtp62-tRBu2VB81Vk/edit#gid=1702375523
https://docs.google.com/spreadsheet...8OxQNG2VvD8qxwseNuXrJZT1Y/edit#gid=2089221261
I didn't want to go whole hog into my problem in this thread but since I have so many knowledgeable folks I will detail them to see what you think. I will be as brief as possible but its hard as its been a long road:
The short - Unburned fuel, oil blow by and/or insufficient air causing intermittent no starts when cold and smoke under acceleration.
The long - I live in Colorado and every winter the car gets harder to start in the cold. The progression was perfect starts for 6 years of owning the car (purchased 2008), then a few hard starts, then more, then a failure to start, then a couple fails, then I installed a frost heater last winter to bandaid the problem and its fine as long as I can plug it in. BUT, without the heater, MOST days it would start fine, then a random day would come along and it would fail to start. I live in Colorado and altitude effects it, the first fail I had was a cold day at 14,000 feet, so something is happening with too little air and unburned fuel/oil.
When I finally get it started it fires very slowly, sounds terrible, blows copious black smoke and sometimes spits carbon powder out of the tailpipe. Its truly awful.
I get smoke on all coldstarts, much more than when I bought the car but not too much unless it starts hard. It blows some smoke under normal driving but lots if I drop a gear and mash the pedal. Very noticeable in the mountains. In general my exhaust smells more richly of diesel than it used to, which has been noticed my multiple people.
It never used to do any of this and the problem is definitely progressive over 4 years. Its also bizarre because beyond it only happening on cold days, it doesn't seem to correlate to how cold it is below say, 20 degrees. Its nearly as likely to happen at 20 as at 0, but it will never happen at 40. I do use anti gel every winter.
What I've done:
-Reseal and chem clean injection pump (no change except pump started making a metal on metal sound halfway through the clean so I aborted the process.)
-Many new air and fuel filters along the way.
-New glow plugs, glow plug harness and relay. Everything checks as working.
-New injectors installed by Diesel Land in Golden
-Cleaned intake (I had this done in 2014 and the shop said it was the worst they had ever seen. Ive had it off since and its clear)
-New EGR (it failed and spit oil on my engine so I replaced)
-Compression test (Performed by a shop, everything checks within specs)
-New brake booster line (had a huge crack, though I didn't notice any problem which is weird. I haven't checked for vac leaks, just learned how and will do soon).
-Checked vent puck (working properly)
So now I'm down to:
-Sticky turbo/bearing blow by (I can't afford to replace and not have it fix the problem, seems to be in ok shape but did have some soot and rust. Not leaking lots of oil but I guess I'll never know 100% about blow by without replacing?)
-Vac system issue (should have done first but I'm learning as I go)
-Clogged Catalytic Converter (I happened upon this reading another thread and will check it when the car is up again)
-Faulty MAF (not sure how to check this with my intermittent problem)
-Faulty ECU causing air issues (Not sure if this can be checked without replacing)
Once I fix the problem I will do a new thread/writeup on it, because I want others to benefit from my struggles and it sucks when people don't post what their ultimate problem was.