Ford 7840 fuel problem

[livestock 1]

She stopped in the yard left ticking over we assumed that it had ran out of fuel put some diesel in and bled off as normal. Didn’t appear to be any air in filter or sedimentor and plenty of fuel to the pump. After cranking with an injector pipe loosened off the pump it would appear that there’s no fuel appearing. Any advice appreciated I’m wondering if there’s an issue with the stop solenoid if it’s shut?

 

[tweedale terrier]

Have you checked the fuses

 

[livestock 1]

Have you checked the fuses

I did. There was one with a fuel ️ symbol with a line through it and the fuse was blown. I’ve put a new fuse in but appear to have no better results. I’m not convinced it had ran out of fuel now.

 

[livestock 1]

The fuse is still intact ie not blown

 

[tweedale terrier]

Can you check the voltage to the stop solenoid, or just run 12v to it to try.

 

[livestock 1]

Can you check the voltage to the stop solenoid, or just run 12v to it to try.

Ok so I assume there’s power to it to open it to run? Then no power to shut fuel off? I did take the wire off and ran a positive to it from the battery but no better! I had wondered if it ran at less than 12v and I’d done it in

 

[tweedale terrier]

Pretty sure it will be 12v. If you are feeling brave take the solenoid out and remove the plunger. Refit the solenoid and try. The only problem with that is you will have to stall the engine to stop it.

 

[livestock 1]

Pretty sure it will be 12v. If you are feeling brave take the solenoid out and remove the plunger. Refit the solenoid and try. The only problem with that is you will have to stall the engine to stop it.

Ok should it click or should I feel a vibration when I put the wire on and off? When I was on with it there wasn’t much life to be noticed. Hasn’t been too keen on starting recently either

 

[tweedale terrier]

You should hear/feel the plunger move when powering up but it will be quite faint.

 

[livestock 1]

You should hear/feel the plunger move when powering up but it will be quite faint.

I had the wire on and off umpteen times and I couldn’t feel anything. I will take it out and remove the plunger to see if that cures it. Is it hard to get plunger out? That fuse blown that I renewed seems suspicious too

 

[forblue]

Lot of these suffered with solenoid shorting out, as suggested remove solenoid be careful and retain spring and plunger refit just solenoid and retry or you can switch on ign and hold solenoid body on an earth and it will pull in plunger if ok, making certain you have 12v on terminal first.............to stop stall engine.

 

[tweedale terrier]

No this bit just pulls/falls out.

 

[livestock 1]

Ok if that’s all it is I will be over the moon to be fair. I was hoping there’d been bother with these and that’s all it is. I have changed loads of fuel filters on this tractor and can usually bleed the thing off easily you get to know how long it takes to get it to start after a while and it looks like there’s something a miss. Even with a cold engine on a cold day something isn’t right as well as the fact I didn’t actually find any air.

 

[livestock 1]

Thank you both for all of your help much appreciated

 

[forblue]

Have also had a few give problems with the hand primer on top of the filter the diaphragm get's tired, i also had one that blocked the 90 deg elbow where it joins the tap on pre-filter bowl the cause was flakes of plastic from fuel tank when holes had been cut in it when fittings had been added, even after removing and cleaning tank it did it for another two or three time's what i found strange was only the elbow got blocked and it never happened to any other tractor we sold..........

 

[livestock 1]

Have also had a few give problems with the hand primer on top of the filter the diaphragm get's tired, i also had one that blocked the 90 deg elbow where it joins the tap on pre-filter bowl the cause was flakes of plastic from fuel tank when holes had been cut in it when fittings had been added, even after removing and cleaning tank it did it for another two or three time's what i found strange was only the elbow got blocked and it never happened to any other tractor we sold..........

Yes this one has had a new hand primer fitted a few years ago as it was drawing air there. The symptoms were serious smoking on overrun and running badly. I also have had some rubbery stuff blocked in that elbow near the tap on the pre filter. Mine has a restricted pipe fitting on the elbow that blocks. I’m hoping that it’s the solenoid. Fuel to pump and no fuel coming out would point to that hopefully

 

[fermerboy]

Its most likely the solenoid, they are a common problem.
As said if you power it up by running a wire to the starter or battery for a live you should hear or feel a click, I usually keep my hand on the pump and touch the wire to a live, and you will feel it, alternatively get a bit of wood 12" long and press it to the pump with the side of your head and you will definitely hear the click.
Its no big deal to take the plunger out and run it without, stall to stop though.

Check that the pipe to the tank isn't porus and shes losing the prime at tickover, ours have near all been replaced by a rubber pipe over the belhousing down to the tank.
As said the primers are crap, We've one thats been replaced 3 times now.
That and a blockage somewhere, usually the elbow or the little tap, mine blocked there in the middle of the road, just managed to get her half on the verge.

 

[livestock 1]

Its most likely the solenoid, they are a common problem.
As said if you power it up by running a wire to the starter or battery for a live you should hear or feel a click, I usually keep my hand on the pump and touch the wire to a live, and you will feel it, alternatively get a bit of wood 12" long and press it to the pump with the side of your head and you will definitely hear the click.
Its no big deal to take the plunger out and run it without, stall to stop though.

Check that the pipe to the tank isn't porus and shes losing the prime at tickover, ours have near all been replaced by a rubber pipe over the belhousing down to the tank.
As said the primers are crap, We've one thats been replaced 3 times now.
That and a blockage somewhere, usually the elbow or the little tap, mine blocked there in the middle of the road, just managed to get her half on the verge.

Yes thanks I will check the solenoid first then go from there. I can’t see any air in the system and usually when it blocks near the tap primer button is sucked in so I will start at solenoid. Thanks for the advice

 

[livestock 1]

Took solenoid out today tested it with a live no life. Took plunger and spring out and started straight away. Thanks again for the information off everyone