JD X749 Dying after 30-45 minutes

[Egon]

There may also be a thermistor involved. About ten dollars.

 

[Mike VS]

I assume that you have a connector that is used to hook the solenoid up to the tractor's wiring harness. Which side of that connector did you hook the test lights up to? What I'm getting at is if the connector was being tested also. I believe that the hold-in coil only draws about a half amp. You mentioned warm wires, and a half amp probably wouldn't warm up a wire. A poor connection or a bad crimp might. I might also be inclined to bench test the solenoid my itself to see how it performs long term.

I don't recall saying anything about a warm wire, there is nothing like that going on. I wired the lamp by slipping the wire into the plastic connector leading directly to the solenoid. The red wire was the hold in and the white was the start. There is a black which is ground. As for removing the new solenoid again and bench testing it we'll see, but remember the problem lasts for seconds and then it will restart. Yes, it will die again soon but how would you be able to reliably bench test it under these circumstances?

 

[Mike VS]

There may also be a thermistor involved. About ten dollars.

Talk to me... What is it and where is it? I know what a thermistor is but am not aware of any being on this unit. I was thinking right from the beginning that it was some sort of sensor.

 

[Mike VS]

I misread your earlier comment. I would take the solenoid out and apply voltage to it and let it set to see what happens. The more I think about it, the more I think it's doubtful that both solenoids would have identical performances.

The graphic below questions your bulb hookup. One way will check the connector and one way won't. It sure would be nice to have a diagram to see if other connectors are involved.

Since I'm not there and don't have a schematic, I'd be inclined to see if I could activate the injection pump manually so it's set to always run and see the the problem disappears or not.

View attachment 658444

OK, I see what you are explaining about the connector. Yes I put the wires on the solenoid side.
As for two solenoids acting identical, I contribute that to it not being the problem. Am I wrong?

 

[radios1]

maybe just keep it as it is, until enough members and yourself agree on the proper fix??.. there will be a lot of sidetracking first!..

 

[Mike VS]

maybe just keep it as it is, until enough members and yourself agree on the proper fix??.. there will be a lot of sidetracking first!..

I agree. I'm going to cut some more grass in a few days and will ponder it some more then.

 

[crazyal]

Is your fuel filter clear or is it the metal type? If it's the metal type when it dies I would quickly unscrew it and see if it's full of fuel. I had a similar problem on my backhoe and the tractor would just suck the fuel out of the filter. Once empty it would die. If it sat the fuel would slowly fill it back up. The fuel tank is a part of the frame and is tall so when it's half full or more the level is above the filter and when it was empty it's below. When empty the filter wouldn't fill back up. It turned out to be a bad fuel hose.

 

[Mike VS]

Is your fuel filter clear or is it the metal type? If it's the metal type when it dies I would quickly unscrew it and see if it's full of fuel. I had a similar problem on my backhoe and the tractor would just suck the fuel out of the filter. Once empty it would die. If it sat the fuel would slowly fill it back up. The fuel tank is a part of the frame and is tall so when it's half full or more the level is above the filter and when it was empty it's below. When empty the filter wouldn't fill back up. It turned out to be a bad fuel hose.

No, its plastic I think with a replaceable element, but it is transparent and I think that is a great idea. It's very accessible and would be an easy look see. Thanks!

 

[Mike VS]

UPDATE: Today I cut more very tall grass putting a moderate load on the motor. I started cutting and in exactly 55 minutes it died. The whole time I was cutting three things were being tested; First the fuel cap was unscrewed and was loose checking for a failure to vent. (This was done before but I'm starting to doubt my own results.) Also the test light was connected to the fuel solenoid and was brightly lit in my view testing any voltage failure to the now NEW solenoid. And listening to another contributor, I checked the transparent fuel filter housing making sure it was full before and after dying.
Upon dying the light never even flickered and stayed lit until the ignition was turned off. Also the fuel cap was still completely loose eliminating any fuel vacuum issues. And lastly, the filter housing was still completely full of fuel.
I waited 1 minute, restarted it and finished my cutting consuming exactly ten more minutes. It did not die again today. What am I missing here?

 

[mini14]

I have a tlb that has a 3tnv84 engine in it that acted similar. I replaced the electric fuel pump. It uses a pulse diaphragm type of pump that gets weak over time..i replaced it with hep-02 fuel pump, no problems since. Yours might be strong enough to pump a small amount of fuel. I would hear my old one running but the pulse was weak, I can hear a huge difference between the old one and new one. for $20 its worth the risk I think