Injection Pump, Lift Pump, blown motor?

[dirtcurt]

Well after the last thing my 1981 300Sd has pulled I am wondering what to do. I have changed and replaced and adjusted almost everthing chasing a rocking, missing motor. It seemed like #3 cylinder was the culprit. Then I fixed the pressure line to the ALDA valve and it came alive. The motor has 175k on a broken odometer. It looks super clean and when at 2-3 thousand RPMs it is so smooth and noise free. But it has a rock at idle. Then it started to get worse. I climb a 5 mile grade that gets me to 2500ft. My first 5-10 trips to work(25 miles one way) it pulled the hill at 65 mph. Then it started to slow. It started to also seem to not want to go over 4k and would not shift to high gear from there even on flat ground. It felt like it hit the governor and would not go higher than 4k even in neutral. The last trip up the hill it slowed even further to 3500rpm and 35 miles and hour. The engine starts a little rough cold then warms and runs great with tons of horsepower for a few miles, but soon fades with a high rev or warm engine. After the 35mph trip up the hill I nursed it home starting out with a power check and it pulled great cold. I drove it home and was easy on it the whole way. It ran normal. I stopped at my automatic gate and waited for it to open.

All of the sudden the engine starts to shake like it's running out of fuel with large amounts of white smoke out the tailpipe. This thing is shaking so bad my instinct was to get out, it was going to blow up. I have never felt an engine shake so bad, worse than even a Cessna startup or when I blew half of a clutch pressure plate out of a International 60 series. Then it started to smooth enough to get it to my shop. I wanted to see if the lift pump was working and I wanted to see if I could find the problem while it occured. The engine started to smooth and the smoke got better but it would rev to 4500rpm the fade back to 3500 in neutral like a governor stepped in. I pulled the cigar return line and it had a 4 inch jet of fuel at 2k. Then I filled a 5 gallon can in about 10 minutes with a section of fuel line. Volume seemed more than enough but pressure was unknown but would not blow a unclamped hose off when it was plugged with my thumb.

Does this sound like an injector pump problem, lift pump, blown motor or what?

Some other things: Blowby in it's current state will not blow off a plastic cap. The car sat for six years. I currently have full synthetic oil in it. It does not lose oil on the dipstick, no oil in cooling system or water in oil. And a new gold RD bolt.

I have a known good 84 IP on another spare engine. Would it be worth checking out the 1981 IJ pump or swapping the 84 into the 1981?

I am really tired at this time so I may have things off on the post, sorry.