W123, Diesel Engine Repair

I have a two tank SVO system on my Merc with 310,000 Kms on the clock - 100,000 Kms are mine most on SVO. I have never been stumped, held up or broken down before. The engine starts and shuts down on diesel. The problem- I was away for a week and my Merc sat idle. When I came back the Merc started hesitantly (low battery). I drove about 20 Kms and the next day she would not start for love nor money; totally dead. Not even a kick from one cyllinder. I checked; Lift pump ok, replaced with electric lift pump & still no go. IP moving fuel when lines cracked. Cam timing marks and harmonic balancer marks line up ok. Valve clearance not binding, Glow plugs working, has the Mercedessource fast plugs installed. Best thing ever. The injectors were re-newed 8 months ago,

I've recently replaced the nozzles with your kit for my 300CD non turbo. The car ran great for two days, then it quit in a big way. I've replaced the filters,lift pump, bled the air out of the system and can now only get her started with the fast idle turned up. Lots of smoke, I mean LOTS of smoke and when the temp starts to come up and I turn the idle down she dies. She'll restart with the idle turned back up, and still all the smoke. I'm getting ready to pull the Injection Pump to have it gone through, or is there something that I'm missing?

1985 300 TD Wagon

Can anyone shed light on how to properly test a 617 Turbo Diesel Transmission Vacuum Shifting Valve? (See MercedesSource item BCM-COMTVSA for reference.) I have a used one that looks in good shape but is untested - so of course I want to check if it is actually in good shape before throwing it in. Thanks!