I hate to quote that long segment, but this sounds like exactly what happened to my truck. Right down to the replacing of the starter, and it working for a while but the problem returning, and the pull starting it with another truck, and replacing the batteries. My truck is a '93 7.3 IDI (InDirect Injected) factory turbo, 4x4, 5spd, extended cab, 220k miles. When i'd try to crank my motor over while warm, the engine would roll over about 1/2 way and jam - hard, and when you let off the key, the engine would roll back that 1/2 turn it spun. My engine problem (believed to be from cavitation) was allowing coolant to enter the cylinder, and sit on top of the piston. When cranked over, it would hydro lock. only after the truck cooled down, and gave the coolant time to seep through the rings of the pistons, would it start again, and the truck proceeded to burn more and more coolant progressively. Oil soon looked like milk, and the engine has been deemed a loss. Which is a shame, because even tho it burns water like a
steam engine, it still runs and idles great! I've torn the motor down, removing the heads, and have seen the water rings and rust lines in the cylinder (drivers side cylinder nearest the firewall) where you can tell water has been sitting in there. Replacing the head gaskets (twice) and rebuilding the oil cooler proved useless for my situation (huge bummer) :boohoo:.
Is your truck using/burning coolant I wonder?
Also, if I held the key in the start position after the engine started to crank and jammed, the cable running to the starter would start to smoke and blister withing just a few seconds. :/
I think this got off topic from the original post, but I had to let out some frustration. Parting words, it's my opinion, a non-turbo IDI is a half million mile motor, if cared for. it's just going to be a slow half million miles.
Powerstrokes are made for the turbo, and have proven to last a half million miles with a lot more power.
Thanks!