4120 won't start

[tinsnip]

Greetings folks. Lovely day here in Maine except my 7 year old JD 4120 won't start. It's bumming me out. It was yesterday when I jumped on and turned the key. For the first time ever it just cranked but wouldn't fire. Popped the hood and after a look around, discovered that a critter had chewed through a wire. Went to dealer and took the old connector and a pic of where the wire traced back to (see photos). He said something about it being the "fuel lift" and was kind enough to sell me just a set of connector pins that fit in the old snap-together connector. I added a bit of wire with butt-end connectors, attached the pins and inserted them into the sockets of the connector, put it all together and... no joy. For the heck of it I bled the fuel line of air at the filter and tried again. Nope. Same thing, crank but no pop.

Is it possible the "fuel lift" is bad? (Not really sure if that's the correct name of the thing). Anyone have any other suggestions? I'd run the tractor the day before the trouble and all was fine. Scratching my head and falling behind. Your advice appreciated.

Thanks!
Tim

 

[CinderSchnauzer]

I'm no diesel expert, but if the tractor was running before, if it cranks, if it's getting air, then fuel is the only other variable. My Cat C-12 ran out of fuel and it took the "experts" two days before they finally figured out how to properly bleed the air out of the fuel system and then it started immediately. Friends in my MH group are always reporting their diesel will not start. If it cranks the problem, almost invariably, is air in the fuel system. Can you safely crack an injector line and see if fuel is being delivered?

 

[tinsnip]

I was thinking of trying that, and someone else mentioned it as well. So I'm going to give it a go tomorrow. Thanks!

 

[Egon]

The second picture showed what may be the fuel shutoff solenoid. If you can't hear it clicking when the key is turned it's time to start checking the shutdowns and other electrical connections.

 

[beenthere]

I agree with Egon's conclusion, and it is part no. RE526570, called by jd parts as the Engine Performance Solenoid, and I'd only add to double check the electrical connections that were performed on the wires just to be sure they are making contact.
But for sure, listen for the "click" as Egon suggests.

 

[tinsnip]

Thanks to both of you. It's too late here to try it, but now that you mention it, I don't remember hearing that click during the problem but do remember it from typical start-ups prior to that. I spent some time trying to make the connections as solid as possible this morning but I'm not a master mechanic by any means. Given that I had to extend the wires and make an extra connection, there's room for error. The easier thing might just be to replace the solenoid.

 

[tinsnip]

No click when the key is turned so I suspect that either my electrical patch isn't working or the solenoid is cooked. I've ordered that part which will include an intact wire/connector and eliminate my potentially faulty patch job. Anyone have an idea about the degree of difficulty to swap out the solenoid?

Thanks again,
Tim

 

[beenthere]

Looks like 1 bolt and a clevis connector that would have a pin to remove. Should be an easy switch if access is reasonable.
Cleaning good around the area would be a good idea before commencing the swap.

I'd make sure that your electrical wire problem didn't short out and cause a fuse to be blown, thus your possible problem, before putting on a new fuel shutoff solenoid.

 

[tinsnip]

Today I installed the solenoid (had to wait for UPS) and was rewarded by an immediate start. And then crushed when it quit after about 15 seconds and would not start again. The solenoid is working fine but it's still not getting fuel. Something else is at fault. Thinking it might be the fuel filter, I changed that too and still no joy. The only thing I see is that the air bleed screw on the filter, which is made of soft plastic, seems stripped and won't tighten. Could that poor seal be enough to prevent startup? I'm lost and a tad discouraged. I've looked everywhere for additional signs of wire breakage or damage and can't find anything. Is there perhaps a fuel pump or other mechanical component that might be preventing a good start?

Thanks!

 

[Egon]

Consider breaking fuel line at the inlet to the injector pump and checking for flow.

Does your booster pump have priming lever. If so turn key till solenoid clicks and then pump for a while before trying to start.??

Make sure the battery is fully charged.

It's an aggravating situation!