Tractor dies intermittantly

[davemhughes]

I believe I found the part........providing that's the problem

 

[CalG]

Dave, Think it over before tossing your cash across the parts counter.

That solenoid valve is OPEN to fuel flow when it is de-energized. Which is when the tractor is turned on and running, or when it's turned off and parked. When the fuel shut off valve is energized is for a short time AFTER you turn the "Ignition key" OFF (that's a poor term for a compression ignition engine). The signal and timer for this function is controlled by the Engine Stop Solenoid Control Unit.

When the timer again cuts off the battery current, the solenoid is denergized, and the valve opens to allow starting the next time.

If the intermittent stopping fault is with the solenoid valve, the fault would be that it is getting electrical current when it's not needed.
And the fault for when the engine won't shut off is that the fuel cut off solenoid valve is not getting enough current to fully close.

Two different scenarios. At least in my mind. But both could be associated with a bad diode, triac, transistor or whatever in the controller.

I believe the suggestion to just pull the supply wire to the solenoid would answer the questions. That would imply that the fuel cut off would be non-op, and the engine should "just run". Shutting down would require manipulation of the manual cut off lever. (NO NEED TO RUN A HOT WIRE FROM THE BATTERY. doing so would hold the valve closed, and may burn out the solenoid windings) IDK what Voltage or Amperage is allowed for continuous energized operation.

To the suggestions that the trouble is with any of the safety interlocks such as PTO, clutch, etc. Those circuits effect the starter motor. That is, if the interlock is not satisfied, the engine does not crank when the key is turned./

 

[Jerry/MT]

So its a 40hp turbo SAME. Recently had VR/Alternator issue that with the good help of the forum was able to get sorted and repaired. Well now the thing has suddenly developed an issue where it just sudden dies like the fuel has been shut off. No rhyme or reason. It could do it once the first 5 seconds or 10 times and then run for 5 hours under heavy load with no problem. Sometimes I go out and it runs great and others like tonight it dies 10 times.

I replaced the fuel pump last year, I cleaned the fuel filter at that time. Will water in the system do this?? I posted a short video of what its doing.

In a profound statement of the obvious, something is interrupting your fuel delivery. You have to crank too long to start and then it shuts off and takes a while to re-start. Have you checked the strainer on the tank outlet? if some snotty looking stuff is floating around near the bottom of the tank it could cause intermittent fuel interruption by restricting fuel delivery. Have you locked into the fuel tank to see if you can see anything there? Is your tank made of plastic.? Some times during manufacturing, pieces of plastic swarf ( drill shavings etc) are left in the tank and can cause an restriction. Consider removing the fuel line to the filter and opening the fuel valve fully and see if you get a strong, continuous gush of fuel from the tank out let. if it dribbles or is intermittent, you've found your problem.
Have you checked the line to fuel filter and the filter head itself for partial clogging. What's your fuel filter look like? Just because you replaced it a year ago doesn't mean it stays clean. It's a filter it's supposed to get dirty! Is there a small screen at the inlet to the injector pump or on your lift pump?

Water can get in the tank via condensation so try to keep the tank as full as possible to minimize that and open the water drain regularly to get rid of water at the bottom of the filter housing( if yours has one).

Fuel solenoids are a normally closed spring loaded valve that are held open by turning on the key switch and energizing the solenoid. Is your solenoid staying open when the key is on? A loose connection or an intermittent short to ground can cause a problem and shut the fuel off. Is you battery ground connection to the chasis "bright and tight"?

Systematically do these checks and you should find your problem. Don't buy any parts until you do. Diesels in good mechanical conditions can only be shut off by cutting off the fuel.

 

[davemhughes]

Thank you for the advice. I plan to use it and really try to sort this out. Of course I started it tonight after work and it ran fine with no issues as I let it idle for 15 minutes.

Not just changing parts without solid suspicion that indeed that's the issue is good advice. But sometimes that's what you are left doing to fix things. But I will try the suggestions noted first.

I will first investigate the fuel and plan to just drain the tank and rinse it. Then the filter, I have to get an after market one as everything I get from the dealer takes a while and is stupid expensive. So I will look at that to rule out that area. I will also look for any loose or grounded wires and then dig further into the electrical issue if the other things do not fix it. I will need to first find the controller mentioned to check it out. The supply wire pull is a good idea to check it. The problem is intermittant and hrd to know if I fix it or not as sometimes it runs great and others it is a pain to keep running.

I hate electrical issues with a passion but I need read up and watch some youtube vids on this and get it fixed as winter is coming.

 

[CalG]

In a profound statement of the obvious, something is interrupting your fuel delivery. You have to crank too long to start and then it shuts off and takes a while to re-start. Have you checked the strainer on the tank outlet? if some snotty looking stuff is floating around near the bottom of the tank it could cause intermittent fuel interruption by restricting fuel delivery. Have you locked into the fuel tank to see if you can see anything there? Is your tank made of plastic.? Some times during manufacturing, pieces of plastic swarf ( drill shavings etc) are left in the tank and can cause an restriction. Consider removing the fuel line to the filter and opening the fuel valve fully and see if you get a strong, continuous gush of fuel from the tank out let. if it dribbles or is intermittent, you've found your problem.
Have you checked the line to fuel filter and the filter head itself for partial clogging. What's your fuel filter look like? Just because you replaced it a year ago doesn't mean it stays clean. It's a filter it's supposed to get dirty! Is there a small screen at the inlet to the injector pump or on your lift pump?

Water can get in the tank via condensation so try to keep the tank as full as possible to minimize that and open the water drain regularly to get rid of water at the bottom of the filter housing( if yours has one).

Fuel solenoids are a normally closed spring loaded valve that are held open by turning on the key switch and energizing the solenoid. Is your solenoid staying open when the key is on? A loose connection or an intermittent short to ground can cause a problem and shut the fuel off. Is you battery ground connection to the chasis "bright and tight"?

Systematically do these checks and you should find your problem. Don't buy any parts until you do. Diesels in good mechanical conditions can only be shut off by cutting off the fuel.

I don't believe you have stated the correct operation for the fuel cut off solenoid as fitted to the SAME tractors.

i.e. "Electrical "ON" is fuel flow "OFF". It may be other wise on other tractor makes.

 

[CalG]

A different angle

Observe the tach-o-meter and other instrument panel indicators. Do they drop out at the same moment the engine begins to falter? If so, Key switch/ circuit is suspect.

 

[Jerry/MT]

I don't believe you have stated the correct operation for the fuel cut off solenoid as fitted to the SAME tractors.

i.e. "Electrical "ON" is fuel flow "OFF". It may be other wise on other tractor makes.

I don't understand why a simple fuel shut off would need an elaborate controller with the requisite logic when the only purpose of the fuel solenoid is to cut off the fuel delivery to the injector pump and open it again when starting- a simple binary function- of and on!. In the old days this was done by stop cocking the fuel with a cable actuated shut off. Why not just a simple solenoid cut off valve? I'm not trying to start an argument but I certainly don't see the value of a device as you suggest. Could you explain the benefits of such a system?

 

[davemhughes]

A different angle

Observe the tach-o-meter and other instrument panel indicators. Do they drop out at the same moment the engine begins to falter? If so, Key switch/ circuit is suspect.

When it dies it's like you turned the key as it all goes dead. Another lead to investigate.

 

[CalG]

I don't understand why a simple fuel shut off would need an elaborate controller with the requisite logic when the only purpose of the fuel solenoid is to cut off the fuel delivery to the injector pump and open it again when starting- a simple binary function- of and on!. In the old days this was done by stop cocking the fuel with a cable actuated shut off. Why not just a simple solenoid cut off valve? I'm not trying to start an argument but I certainly don't see the value of a device as you suggest. Could you explain the benefits of such a system?

I can't put an advantage to the system either, but that is what is fitted to the tractor I have. It's the symptom of running on after the ignition switch is turned to off that leads me to say the fuel valve is open when the solenoid is de-energized. It could be some other control or input. I've read the service manual, and thoroughly investigated the operation of the Control Unit. It's a "Black Box" to me. Three wires in. One is fused 10A directly from the 12v DC bus, two come from the ignition switch. Two wires out to the solenoid, and a ground.

The problem could be as simple as a loose fuse holder on one of several circuits.

ETA These tractors were offered by the SDF group with an air cooled diesel engine as an option. Looking at the wiring schematics for that version, the fuel cut off solenoid is wired "logically". That is, a single wire from the key switch. Although it is a bit confusing in that the single glow heater is in series with the solenoid winding. Figure that one ! ;-)

OK Here is why the system is the way it is.
Woodward | External Solenoid Control Electronics

It takes a lot of force to actuate the fuel valve. That goes along with how solenoids function. Force and distance etc.

 

[CalG]

Just some additional "digging"

There is on my Hurlimann a fuse block on the engine side firewall right side. It holds an assortment of 10 amp fuses .

There is also a fuse block UNDER THE INSTRUMENT COWL that holds the 70 AMP heater fuse, the 30Amp General fuse and a 30 amp fuse for lighting. Pulling the steering wheel may be required to check those big fuse connections.

from the wiring diagram 30amp P3M, 10amp P1, and 10amp P3 all are connected to the control unit in some way.
P1 is the direct connection to battery 12v. Fused, but unswitched. (It also connects power to the winkers control??)