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Discussion Starter · #1 ·
1993 Ford F250 7.3 idi non turbo - Yesterday I went to shut my truck off, turned key off and removed it and realized it was still running. Put it back in cycled it a few times until the rpms slowly dropped down to nothing and it died. Started it back up and it did it again, but this time when I slowly cycled the key it shut off like normal. I'm assuming it is something with fuel pump solenoid. Has anyone had a problem like this? Is it something in the column with the key switch or is it the solenoid iteself? Any info, advice? Thanks, Glenn
 

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I would start at the switch on the column. Not the key cylinder but the actual switch on the column.
 

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The fuel pump is mechanical; no tie to the electrical system. There's a fuel shutoff solenoid (FSS) on the injection pump, which is energized with the key in the RUN position. If the switch (see above) checks out okay, check for voltage at that solenoid (middle connector on the IP) with the key on and off. If voltage goes on/off at that connector with the key, then next time it happens, try disconnecting that connector and see if the engine stops. If it keeps running, or stalls slowly as you described, then the solenoid is suspect.
 

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If there is no voltage to the FSS and it still keeps running, the solenoid is sticking, the armature/plunger has a very short stoke. If the key had been left on for a long period without the engine running, the FSS coil gets very hot without fuel flowing around it, the coil insulation is varnished and can melt and get on the coil armature/plunger, causing it to stick or return slowly. The solenoid coil is in the IP cap, it's the larger one of the two. If you remove the cap, refer to the pic when replacing it. A runnaway engine can occure if it's not placed there.
 

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Discussion Starter · #5 ·
Ok I'm going to check it out after work. I have a feeling its the switch in the column. Because if I turn it slowly and firmly it would shut off no problem. I'm the kind of guy that shuts truck off, depresses key release lever and whips keys out all in one quick motion... while still rolling to a stop... We shall see. Thanks
 

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Discussion Starter · #6 · (Edited)
I've actually never messed with the IP on my truck. Anyone have a picture or diagram of the solenoid and its location? It will be getting dark by the time I get home from work and I don't want to be out there searching. Is it actually in the IP?

And couldn't I start the truck, unplug the red wire to solenoid, and determine if the switch is good or bad like that? If I unplug it and it shuts down, that should mean the solenoid is working. Right? I'm cutting off the power, much like the key switch does. Madpogue said it too I just realized
 

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^^^^ Yes, disconnecting the FSS while the engine is running SHOULD kill it. That would indeed narrow down whether it's a switch/wiring problem up to the FSS, or the FSS itself.

There are three single-wire connectors on the injection pump (I think there are more on an automatic-tranny truck). The one way up front, by the idle stop lever, is the cold/fast idle solenoid. It's an external solenoid you can see, with a plunger. The one halfway back is the FSS. The one furthers back is the cold advance solenoid. It's that one halfway back that you want to try disconnecting.
 

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Discussion Starter · #8 · (Edited)
Turns out the terminals were corroded. I cleaned them up and seems to have fixed it.
Now onto the next problem. Water pump...

But now that I think about it, corroded terminals would act the same as unplugging them. The connection would be lost. I did unplug them while running and the truck shut off, so must be the switch in the column.
 
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