CM870 code 259 Fuel shutoff solenoid

[Rawze]

About 3 years ago, I had a friend who came over here who's engine ran for about a year where it would stumble for several seconds after shutting off the keyswitch. Then all of the sudden one day, it ran for almost 2 minutes after shutting off the key in the dash. Turns out the fuel shutoff solenoid was sticking and going bad. Replacing it though, only solved the problem of staying on for a couple minutes. It still stumbled/ran for several seconds when shut off even with the new one. It was not until he replaced the metering actuators, that the whole problem got solved.

I also had one guy come here who's engine would rev up a few rpm at idle randomly, and would also hesitate several seconds when shutting down. I watched his commanded fuel flow in the ECM and it was commanding zero fueling when it would do this. His was a bad metering actuator as well.


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I don't know about the CM870, but my CM871 (same IFSM module) shut off in the middle of the interstate, no warning whatsoever about 3:00 A.M. for a similar code. The fuel shutoff solenoid died. I gutted, then re-installed the outer shell and gasket so that I could get the truck home to fix it properly.

The truck ran perfectly fine without the guts in it, and the engine did not have any hesitation shutting off at all. I was fully expecting to have to unplug the ECM to get it shut off once I got it home, but was surprised find that it shut off just fine. -- It has now been like that for more than a year, I decided not to replace it so that it does not put me on the side of the road again. Truck runs fine with the fuel shutoff solenoid gutted and shuts down right away when the key-switch is turned off.

- It is just speculation, but this leads me to believe that since my own truck has zero hesitation in shutting off without the shutoff valve in place,.. a leaky fuel actuator would definitely cause one to stumble and have issues like not shutting off for several seconds. This would likely be true even if the shutoff solenoid was working until fuel pressure fell off to the point that it could no longer feed the cylinders.

-- So in your situation,... A sign of worn out/leaky actuators perhaps?? Who knows. If one is worn out, they all likely are if they are the same age. Not saying that your power and other issues are the actuators, but it is something to think about.