thanks for the comments.

I figured out that I blew the cylinder-hydrolock diagnosis right after I finished. Nice.

I tired lifting the purple wire from the GP circuit as suggested above. I'm not sure how much of an improvement it made. A seasoned Mercedes mechanic told me to start up at 2000+ rpm to avoid smoke. This does work, if I keep the rpm's above about 1600, and if I sit there for 4 minutes waiting for the block to heat up.

I wondered about the diesel fuel hydrolocking as well. Seems that it would be easier to overload a cylinder with fuel from an injector than from a gasket leak, but I have no facts on my side. I do know that the injectors are out of whack by the nailing and unburned fuel. I've never smelled anything like coolant in the exhaust.

Can a cylinder fail to ignite because too much fuel is sprayed, as opposed to just a bad pattern?

Will advise about changes.

Thanks!