fuel shutoff solenoid on the cummins 8.3

[74M35A2]

I go through this also. My fuel gauge was nuts for a while, so I ran it out several times. Yep, my dumb fault, and yes more than once. OK, so, upon doing so, with long cranking, my stop solenoid would be ok at first, but as the cranking continued, voltage dropped, and the solenoid would let go and flip to the stop position. You don't know this is happening if in the truck with the hood closed. At this point I had to zip tie it into the run (retracted) position.

This solenoid has 3 wires: ground, pull, and hold. It has 2 coils inside of it, a strong and fast "pull" coil that can only be used momentarily or it will overheat, and a "hold" coil which is rated for continuous engagement without overheating. That is just a little FYI on how it works. A starter solenoid is much the same, depending upon the maker.

Personally, I like the idea of removing it completely. Would love to get an air starter and just throw all of the electrical and batteries away if lights were not required for street use.

 

[gunsgreg]

I've never trusted the solenoid since I had to replace it. Appreciate the info on eliminating it altogether, it's on my mind.

 

[datadawg]

This has been an on going problem with this engine since the trucks were fielded. I was in a unit that changed over from the 800 series truck straight to the cargo 900A2 series. At night in the Motor Pool you could hear the solenoids de-energizing with an audible "clicking" sound.
Drivers that were unaware of the problem would drain the batteries trying to start the trucks. The Standard Operating Procedure was to lift the hood prior to cranking the truck for the first time each day and inspect the solenoid when engaging the battery switch (this was supposed to be done anyway as pre-trip but you know lazy Privates). If it would not operate then "Soldier B" would hold it open while the driver cranked the truck. Usually once it had energized you were good for a few days if the truck was started every day.
:

My truck will crank, but won't start. Can someone post photo of solenoid and what part you need to manually hold open? I am sorry for this naive request, but I don't know what the solenoid looks like and I am desperate to try this.

 

[WillWagner]

Will am I crazy or did I read that the voltage for opening the solenoid was 24v as you are cranking but drops to 12v once the engine is running? Wouldn't that allow just one battery to cause the problem?

Sorry, just saw this. No. there are 12 and 24 volt FSOVs. The solenoid has two coils in it, pull in and hold in..... A, red wire, hold in......B, white wire, pull in...C, black wire, ground. Pull in is wired to the crank circuit, some OEMs wired to the starter solenoid, this will pull the FSOV up when cranking. Hold in is wired to an ign on/run circuit so when the switch returns from the crank position to run/on, the coil will continue to hold the FSOV up to run. The ground, kinda self explanatory, It needs to be a good ground with less than 10 ohms of resistance back to bat neg, (this is the spec, but a ground with 10 ohms cold will do nothing but get worse as things heat up, less that 3 is my goal). Both the 12 and 24 volt FSOVs operate both coils on their specified voltages. Only the resistance through the coils is different

I'll see if I can dig up the specs for the system

 

[WillWagner]

Cummins FSOV Specs

Here ya go....Want me to sticky this?

 

[tobyS]

My truck will crank, but won't start. Can someone post photo of solenoid and what part you need to manually hold open? I am sorry for this naive request, but I don't know what the solenoid looks like and I am desperate to try this.

Sorry, don't have a picture to post but will attempt to talk you through it. Look on your fuel pump and you see the throttle lever and the solenoid? In the off position, that solenoid is out and prevents the arm from rotating forward...which stops fuel in.

Mine is not pulling in, but as said above, the holding coil will still hold once it's manually pulled in. So turn on your switches and then go manually push the plunger up and into the body of the solenoid. Push it clear up and it will (probably) lock up into the position, (held electrically), until you turn it off and the hold circuit releases. Once manually pushed up, with the hold circuit holding the plunger up, the truck should start.

 

[datadawg]

Sorry, don't have a picture to post but will attempt to talk you through it. Look on your fuel pump and you see the throttle lever and the solenoid? In the off position, that solenoid is out and prevents the arm from rotating forward...which stops fuel in.

Mine is not pulling in, but as said above, the holding coil will still hold once it's manually pulled in. So turn on your switches and then go manually push the plunger up and into the body of the solenoid. Push it clear up and it will (probably) lock up into the position, (held electrically), until you turn it off and the hold circuit releases. Once manually pushed up, with the hold circuit holding the plunger up, the truck should start.

I managed to get the truck started. Have no idea what I did that worked though. The TM dealing with crank but no start condition was not particularly helpful.

I drained a little bit of fuel from the bottom of the oil/water separator canister. I then pumped the manual fuel prime button until my arm was about to fall off. I lost count but probably well over 100 pushes. I also took apart the solenoid and reattached the rubber boot, it had slid down before.

The truck started somewhat unwillingly, but start it did. Again not sure what cured the no start condition. I had pumped the manual fuel prime button several days before for a hundred times and it did not cause the truck to start at that time.

 

[tobyS]

I managed to get the truck started. Have no idea what I did that worked though. The TM dealing with crank but no start condition was not particularly helpful.

I drained a little bit of fuel from the bottom of the oil/water separator canister. I then pumped the manual fuel prime button until my arm was about to fall off. I lost count but probably well over 100 pushes. I also took apart the solenoid and reattached the rubber boot, it had slid down before.

The truck started somewhat unwillingly, but start it did. Again not sure what cured the no start condition. I had pumped the manual fuel prime button several days before for a hundred times and it did not cause the truck to start at that time.

Did you confirm that the solenoid is retracting? If that's the issue, you will have another opportunity.

 

[datadawg]

Did you confirm that the solenoid is retracting? If that's the issue, you will have another opportunity.

It was retracting when truck started, but I did not know enough about this to look at it when it wasn't starting, so not sure whether it was working before. Maybe it's an intermittent fault and if it malfunctions again, I will know what to look for.

 

[Tinstar]

There is a 8mm bolt on the fuel line next to the small water separator/filter.
Pump the primer, loosen that bolt and any air will come out.
Tighten bolt back up and she should bust right off IF that was the issue.

Mine was doing same thing after filter change and no amount of pumping that thing would get it to start.
I searched the old threads and found out the info on the bolt.

Worked like a champ.

 

[infidel got me]

You may have a bad lift pump also. If the solenoid is working properly and truck still wont start. I had this problem with mine. There is a bb inside pump that will roll around to a certain spot and will allow truck to loose prime. Truck would start all day- hot or cold- then randomly I would loose prime. Quite a pita when stopping for fuel, running into a store, etc. I had to pop the hood and prime till my thump fell off. I purchased a new one from my Cummins dealer for under a $100. Make sure you get a new gasket with it. Dealer part from Cummins, but stamped made in china on it---- go figure.

 

[datadawg]

There is a 8mm bolt on the fuel line next to the small water separator/filter.
With engine off, pumping the primer, loosen that bolt and any air will come out.
Tighten bolt back up and she should bust right off IF that was the issue.

Mine was doing same thing after filter change and no amount of pumping that thing would get it to start.
I searched the old threads and found out the info on the bolt.

Worked like a champ.

I recall reading somewhere about this bolt and even brought out an 8 mm wrench to try this trick. But I could not find the bolt. I had no idea where to look, though. Thanks for pointing out it's next to the water separator filter.

 

[brakejay]

See arrow. Somebody posted this for me when I was trying to find the vent.
TM pictures aren't of the 8.3.
This little bolt is actually a check valve with a hollow center and a ball in it.

 

[Tinstar]

See arrow. Somebody posted this for me when I was trying to find the vent.
TM pictures aren't of the 8.3.
This little bolt is actually a check valve with a hollow center and a ball in it.

That is from the thread that helped me.
It saved the day!

 

[Csm Davis]

There is a 8mm bolt on the fuel line next to the small water separator/filter.
Pump the primer, loosen that bolt and any air will come out.
Tighten bolt back up and she should bust right off IF that was the issue.

Mine was doing same thing after filter change and no amount of pumping that thing would get it to start.
I searched the old threads and found out the info on the bolt.

Worked like a champ.

Should be a 10mm bolt not 8mm

Sent from my SM-G900V using Tapatalk

 

[Tinstar]

Should be a 10mm bolt not 8mm

Sent from my SM-G900V using Tapatalk

The bolt to the right of the small fuel filter is 8mm
On mine anyway

 

[WillWagner]

See arrow. Somebody posted this for me when I was trying to find the vent.
TM pictures aren't of the 8.3.
This little bolt is actually a check valve with a hollow center and a ball in it.

No check valve there. That is injector return. a 6mm banjo bolt, no screen, no check valve. There are two check valves in the lift pump and 1 at the galley return at the pump, this is the one that makes the low pressure in the pump.

 

[WYomer]

No check valve there. That is injector return. a 6mm banjo bolt, no screen, no check valve. There are two check valves in the lift pump and 1 at the galley return at the pump, this is the one that makes the low pressure in the pump.

Yeah I'm pretty sure the other banjo fiting to the left of the one the arrow is at is the one to bleed. But do both to be sure.

 

[Bendango]

I was thinking of removing my solenoid as well. What is the proper shut down sequence?

When my shut off solenoid quit I just removed it and use the emergency shut off, pull to cut the fuel and push it back in to start. Just remember the proper shut down sequence.

 

[74M35A2]

Which engine?