Dieseling 255

SB Massey

New User
My MF 255 (diesel) that I tried to start yesterday, about 16 F, would not start, that'll teach me not to use the block heater, and kept on trying to start until it completely discharged the battery. Turning the key, removing the key, pulling the kill switch had no effect--starter continued to run. The battery was new, the starter is new. The tractor has done this a few times, but not recently and it has been started at 16 F and a bit colder, without difficulty, albeit with the use of the block heater.

Somehow the starter solenoid remains open even when the key is returned to the run position. I also noted yesterday that the L-S-H shift lever on the right, felt like it would not shift into L. Usually, I think, it needs to be in S to start, it was, but wondering about the difficulty with shifting into L and it dieseling.

Thoughts? Thanks much.
 
If the starter STAYED engaged with the key off most likely the solenoid contact plate "welded" itself to the two heavy contact bolts. A quick rap on the side with a wrench will usually get it to stop. There COULD be a chance the Delco starter has a broken/missing nose thrust washer, that will keep it engaged also. Had that happen on a 265 diesel years ago.
 
You can weld the contacts in the starter by running them low on voltage or too long.

If it does not start, stop cranking.
 

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