My 83 300D (non turbo) is running on 4 out of 5 cylinders. I confirmed this today by cracking the injectors while it was running, and the idle lowered on 4/5, but when I cracked the first injector (closest to the front) the idle remained steady, and some fuel leaked out.

I've ruled out the injectors, since I replaced them a month ago, and the poor performance did not improve.

I haven't done a compression test, but the engine starts up like a champ, and oil pressure is always good.

I spoke to a German Car Mechanic this morning who said that the engine has to be replaced. He was appaulled to hear that I let another mechanic (not a diesel specialist!!) spray starter fluid into the air filter. He said this strips the oil from the engine, and turns the seals to sawdust. He said "don't bother bringing your car in" after this discussion.

My question, is there any hope for reviving this dead cylinder? Any tips, tricks, or "Hail Mary" techniques I might try?

Any help is much appreciated.