Oldblue813

recently went through and resealed my leaking control valve. driving down the road and the truck misses, and then instantly picks up again. runs fine for awhile, (several miles) then does it again. except this time it wasnt a small deal. it fell on its face, i let off the accelerator and then pressed it again and it wouldnt accelerate. let off again and it took fuel and took off like everything was good. never had a minutes trouble with this pump til now. wondering if anyone would know of what could be happening to create this situation or if its something that i might be overlooking?

maybe368

Check the wire to the FSS, it may have an iffy connection...Mark

Oldblue813

i have had a short on my fss before... didnt do this same thing. it killed all the electric and blew the main fuse for the truck. i am not seeing any electric drop out or flicker when this happens. just the truck seems like its pulling air into the injector pump.

j_martin

The FSS is supplied by a switched circuit that goes all over the truck and feeds several critical items, like the OD solenoid. If there's a short in it, it usually takes out a fusible link and shuts down all other items supplied by the same circuit.

That said, if the FSS connection on the fuel pump is loose, it will connect and disconnect. It won't affect any other part of the circuit, or blow fuses, it'll just shut off the pump when it disconnects. It's an exposed .250 tab slide on connection, so you can plan on seeing this fault from time to time.

Clean and tighten the connection and your problems will go away.

This is a very well known, common problem on this engine.

bannerd

Or gut the FSS, of course you will need to shutdown the engine another way. Pull cable or electronic actuator.