Tractor dies intermittantly

[CalG]

It appears these fuel cut off solenoid issues can be perplexing.

Even if you run a JD
http://www.tractorbynet.com/forums/...2-help-interpreting-wiring-diagram-using.html

 

[Jerry/MT]

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.

OK I understand how this solenoid works. it still performs a binary function but it has dual solenoids; a high current solenoid for opening the fuel valve and a low current solenoid to hold it open continuously. There is a timer circuit to only allow the high current solenoid to be energized for about 1 second. If I were designing it I would eliminate the timer and just design the solenoid to have the same pull in force and be able to run continuously. Lower part count = lower cost and better reliability since no timer to fail.

 

[davemhughes]

Wow...lots to soak up.

After work I started it and then brush hogged for 3hrs tonight, never missed a beat. Plan to dig into it in the morning. I am just going to run through as much as possible as what has been suggested and see. I guess the only way I will know if it's fixed is if it never happens again :laughing:

 

[CalG]

OK I understand how this solenoid works. it still performs a binary function but it has dual solenoids; a high current solenoid for opening the fuel valve and a low current solenoid to hold it open continuously. There is a timer circuit to only allow the high current solenoid to be energized for about 1 second. If I were designing it I would eliminate the timer and just design the solenoid to have the same pull in force and be able to run continuously. Lower part count = lower cost and better reliability since no timer to fail.

Jerry

You are absolutely correct, but the reference was only to high light the need for a low energy option. The S+L+H tractor I have has only a single bobbin solenoid, (two wires only, one supply, one return) S+L+H must use a "different" method to reduce the power consumption and heating than does the two bobbin execution. The running on after the ignition key has cut electrical power suggests as much. Today, I pulled the fuse that powers the cutoff control unit directly. The engine remained running. A symptom the OP has had previously.
I'm not saying the OP's tractor is exactly the same as mine, but it is very close. I'm assuming it has similar components due to the commonality of the Mitsubish engine. Mine has a K4F-D I believe the OP has a K4F-DT. All the same excepting the Turbo, manifolds and the fuel injector output.

If you could design a solenoid with the required pull in force and still fit the space envelope, there is a world waiting to beat a path to your door step. Perhaps newer technology could be applied, but the old manufacturing lines have the momentum and cost advantage.

I'm feeling that it is either a soft semi conductor within the control unit, OR a simple poor connection that triggers an inappropriate response from the control unit. I hate to spend $100 replacing a "black box" only to find it was some small tab of metal that needed cleaning and bending. I've been though the connections on my tractor several times without change. I'm hoping the OP will have better success!

 

[Jerry/MT]

Wow...lots to soak up.

After work I started it and then brush hogged for 3hrs tonight, never missed a beat. Plan to dig into it in the morning. I am just going to run through as much as possible as what has been suggested and see. I guess the only way I will know if it's fixed is if it never happens again :laughing:

Systematically check out any changes right after you make the change. Then you'll know what the root cause of the problem was.

 

[CalG]

This description of the shut off function taken from the service manual

3.3 ENGINE STOP SYSTEM
The engine stop system is designed to stop the engine when the operator turns the key to position 徹 (OFF).
The system comprises two main components:
1 - Engine Stop control unit (X21 - X22)
2 - Engine Stop solenoid (X35)
The engine is stopped when the solenoid (X35) is activated.
To do this, the engine stop control unit (X21 - X22) energises the solenoid for a brief period (5-6 sec.) when the starter key
is turned to position 徹 (OFF).
To prevent the engine stopping as result of voltage drops during starting, the engine starting signal is also sent to the engine stop control unit.
[end quote]

Note: X21- X22 and X35 are connector designations.

 

[Johnnyg1200]

OK I understand how this solenoid works. it still performs a binary function but it has dual solenoids; a high current solenoid for opening the fuel valve and a low current solenoid to hold it open continuously. There is a timer circuit to only allow the high current solenoid to be energized for about 1 second. If I were designing it I would eliminate the timer and just design the solenoid to have the same pull in force and be able to run continuously. Lower part count = lower cost and better reliability since no timer to fail.

The reason for the high and low current is it takes more current to move the solenoid than to hold it. If you used high current to hold it the solenoid would fail prematurely. I know it seems like it was over thought but it actually makes sense. You see the same thing with relays. There are momentary and constant duty relays. If you mix them they may work for a while but they wont last.

I have seen problems like yours on the Cummins engines at work and the fuel cut off solenoid is a common cause. I know its not a tractor but the idea should be similar.

 

[CalG]

To further the cause through example.

Yesterday the Hurlimann was used to move a few things around . Started right up and ran perfectly for about 1/2 hour. But then after backing into the shed, turning the key to off only shut down the dash display etc. while the engine kept running. A quick flip of the fuel pump cut off lever shut the engine down no problem.

Today, was a chipper shredder day. About 3 hours at 2200 rpm with everything off the pto. The fuel cut off decided to shut down once in the first hour, then A-OK. I had time to release the pto clutch , set the throttle back a bit, climb into the seat and depress the clutch to satisfy the interlock, then I heard the fuel cut off solenoid "clunk" open. The engine started right up again and worked flawlessly for the remainder. After backing into the shed to put the tractor away, the key was turned to the off position, and the engine shut down as neat as you please. Go figure! ;-)

I'm buying a replacement engine cut off control unit as soon as I can find a source! Can anyone suggest a good D-F dealer that speaks Hurlimann? The nearest identified dealer in on the west coast of New York state ;-)

 

[davemhughes]

I believe these guys are knowledgeable about as they have been a long time Deutz dealer. I think the control cutoff unit is the same on all the Mitsubishi diesel tractor engines. I may need one of those also if the fixes don't work. You have a picture of it and I will look also.

Anderson Equipment Claycenter, KS 785-944-3370

 

[CalG]

I do not have a picture of the unit. just a rectangular line drawing on a wire schematic.

I do have several part references. For the Hurlimann Prince 435 from a copied service manual purchased off ebay some years ago.

Engine Cutout Control Unit Code 008.7630.4
model YMS-1 B
input voltage 9-15
resistance 1.7 ohms

Then from a parts reference for a late model AgroKid The schematic shows a "Control Timer" I6A11-1400.
This application shows an interface with the oil pressure sensor. There is no similar connection shown in the schematic for the Hurlimann 435. I believe this added feature is applicable to the later models only.