Hey, woke up this morning to find out my 94 cummins would not start. Luckily I remembered someone telling me the fuel shut-off solenoids sometimes have issues, so i lifted up on it with the ignition on, heard it "click" into position and the truck fired up which got me to work only slightly late.

Now I'm finding this problem more frequent with the cold weather arriving, is there someway to fix this problem or am I going to have to buy a brand new fuel shut-off solenoid?

Thanks for any input!

 

more than likely its the solinoid, but could be the relay mounted on the fire wall directly behind the injection pump

 

There is a (blue?) wire at the battery that can corrode inside, causing this problem. It's the power wire for the solenoid. Check that, then the relay. The solenoids themselves are very dependable, and rarely fail.

 

wicked! I hope that will be my problem, I know many wires have had corrosion already and I had to replace them.

How exactly do I test the relay?

 

There are 2 power sources for the fuel solenoid. One works with the starting circuit and pulls the solenoid on when starting. The other holds it on after start.

The dark blue wire is a fuse link at the positive battery terminal. If the connector is good check the fuse link to see if it failed. This lead powers the solenoid to pull on during starting. So this is the problem if the relay is good.

It could be that the solenoid linkage needs a little lubrication. I had that problem. I had to lift the solenoid into place to start. Once I lubricated it, I haven't had another problem with it.

 

Thanks for that schematic and all the tips! I have a good idea what to look for now.

 

Only 1 relay is for the solenoid, the other is for the fuel heater. The hold coil only takes a few amps and is run through the ignition. The pull coil needs the relay.