I purchased a "nonrunning" 1990 7.3 that had an air force van transplant engine. The body is rust free. The PO was running it on "veggie oil" till it died but what I drained out appeared to be varnish and WMO in the main tanks with WVO in the bed tank.

The PO told me a new injection pump would fix the no run issue so I wasted some money on a new IP from the Uhaul sale. Still no start. Work started to pick up so I sent it to a repair shop for correct diagnosis.

Long story short, new injectors and new pump (the uhaul IP apparently was ruined by blowback from a broken injector??) got it running with some smoke. I asked for a pressure test and all cylinders are producing an average of 400 except number 5 who is making 38. Yes, 38 as compared to the 390-422.

Do i just drive it till it dies while keeping my eyes out for a replacement engine and, fingers crossed, a turbo??

PS: Niche Diesel in Hornell, NY... don't go there.

 

a low compression cylinder probably has a hole in the piston or the like, is there diesel in the motor oil or anything like that? If your looking for a replacement engine, I can help you tehre, im in MT but its possible that something could be worked out. I got a running engine for sale. I would say keep driving it, your not gonna have the Fuel Economy, or the power that a properly running 7.3 has however.