Cm 870 fuel shutoff problems

[Rawze]

(05-02-2025 )Precisionw900 Wrote:  ...
I hooked up a jumper to fuel shutoff and it fired right up and ran the rest of the day. ...

I hope like all h$ell that you disconnected the wire going to the ecm before you jumpered that solenoid. ... otherwise it burns out the circuit chip inside the ecm that feeds it (ecm commanding it OFF as engine shuts down, and you have it wired to 12volts = a conflict that damages the chip).

and like mentioned above.. you should bang on the ecm and see if it is not a floky ecm.. it is common on those CM870 and CM871's for the ecm itself to randomly shut off as they get old, or if no one has ever changed out the crank shaft damper in the last 500k miles ... higher frequency vibrations take out that ecm when crank shaft damper start not working so well.

BTW: I removed the guts on my shut-off solenoid to get me off the side of the road a long time ago in my own truck, .. I never put them back in...lol.