Early 80's big cam. Truck won't shut off with the key, manual screw works. So I replaced the solenoid, and if you have the manual shut off screw in juuusssttt the right spot, it will shut off with the key. Sometimes. So I'm thinking I've either got a electrical issue not giving enough voltage to the solenoid- but if I screw the manual shut off it pushes it to "almost closed" and then it works. Or- I've got problems inside the shut off valve, and its got gunk on the spool, or the spool portion is leaking? I've never been inside the shut off of a big cam, but I'm thinking my first/next is to get a good 12v coming to the shut off solenoid, and see if that changes things. If not I guess I'll have to dive into the shut off valve itself.
Replace all of it as a unit.
^What she said LOL
Thanks guys.
You owe us a drink.
There is a metal disc with a black rubber like material bonded to one side of the disc. If the material starts to deteriorate it may not fully block off the fuel flow allowing the engine to continue running with the key turned off. Usually when the disc starts to fail the first complaint is longer cranking times at startup after sitting a while.
I was thinking the china supplied shut off
The solenoid was straight from Cummins, I think it said Mexico on the bag, but i wouldn’t want to bet money on that. The whole shut off was supposed to be at Cummins Friday morning. Haven’t had any long cranking time. Truck sets a lot, we’re using it quite a bit right now while we are working on a different truck. It probably set for 6 months last year without moving.
Mexico would be correct.