I was in your exact situation last July. The
engine had sat for 11 years without anything done except to manually turn it every so often. While going through the
engine to get it going again, I found the stop lever wouldn't operate, which led me to find the stuck
fuel rack. The
3gm30 shuts off with the rack in full forward mode, and the
diesel had turned to
varnish in the meantime. No amount of penetrating
oil appeared to help, and I disassembled the top of the fuel injection pump to no avail. The front of the rack locks the injector pump into the case cover.
Long story short, the only way to remove the pump was to unbolt the gear cover, which proved a lot easier than I thought it would be. It did require a gear puller for the belt pulley and
removal of most of the front of the engine, but was not difficult. I used the same gear puller I have for my
propeller. The engine
rebuild manual available online in PDF form is super helpful!
What Compass790 said is also correct - the cam lobes will normally want to catch on the plunger roller, but having the injector pump loose will prevent it from catching as you pull the case cover off. Wotname is also right that there are shims under the pump that MUST go back the same way. Mine were fairly glued to the crank cover with grime.
Once removed, I could disassemble the pump from below and free up the rack. The fuel injector pump is a precision and complicated piece, so take care with disassembly - let a professional clean and put it back together if you're not 100% confident.
Reassembly was reverse order, but with new gaskets, torquing everything to spec - and the
inspection cover needs to be off in order to line up the injector rack with the governor fork.
I have photos of the crank
removal here:
https://www.instagram.com/p/CRXm5aPL4W_/
And a few of the injector pump
rebuild here:
https://www.instagram.com/p/CRkKHMrLsNU/
I hope this helps! FWIW, the engine started up and ran beautifully shortly after finishing the
work.
-Eric