Hi all, been reading the forums for a few weeks now, but this is my first post.

I recently got an '84 190d (w201) 2.2 with a 5spd manual from a friend. He has 2 other old MB diesels, and didn't have time for this one.
The car sat for 10-15 years, partially in a garage and the rest outside. After siphoning out around 3 gallons of old diesel, putting 5 gallons fresh, and charging the battery, it eventually started. Running fine, sounding good.

After running it a time or two, cumulatively around 3 minutes, it made a few loud clunks and shut off. Then we started it again, to hear a terrible sound from the top end. We took off the valve cover, and discovered the hydraulic lifters were mostly if not all bad. These were replaced, along with both fuel filters, oil filter, oil drain plug, motor oil, valve cover gasket, and air filter.

It had a bad clutch slave cylinder, which I replaced and bled after a week under the car. This fixed the clutch issue (clutch pedal wouldn't move) and I know it works now because it'll try and overcome the mostly stuck brakes.

After these repairs, it runs with a similar clunking, but it seems the engine is only running on 2/4 cylinders. With the intake box off, the rear cylinder is wet with black fluid (presumably oil) and is puffing out smoke. The rest run without fluid or smoke. The engine shakes violently, but idles, and can rev up when flooring the pedal.

My question is, what is this wet intake, smoke, and rough running caused by? I have been theorizing that it's a fuel injector issue, but that doesn't make me understand the wet intake.

After cracking injector lines one by one. I've found that the outer cylinders do not affect how the car runs, while either the inner cylinders will disallow the engine from even starting. I can even crack the outer cylinders together without change.

Again this is my first post, so please let me know if I should change anything in the future. I tried to be as specific as possible, as the car has sat for at least a decade.

Any suggestions would be appreciated.