Bad news big repair

[dirttoys]

For the heck of it, I tried a jumper wire for 10 seconds and the tractor started like a champ.
I guess it’s pretty close to “wire up a switch“ time.
Yeah, I know like 30 people suggested it and it always was my “end game” if I couldn’t fix the OEM system (without spending 6k replacing ECU).

I‘m still convinced something else could be wrong other than the ECU, but there’s only so much time I can steal from working in the fields. It needs to be worked on when it’s cold to get the GPS to work and that gets old pretty fast.
I appreciate all the suggestions and the effort by some. Even with the few trolling, it was worth it.

I missed this one when I was poking fun at you, glad you have a work around and can get it going in the cold.

Best,

ed

 

[DieselBound]

Some tractors have glow plugs, some do not. It depends on the engine design and also if the manufacturer decided to use some other sort of starting aid such as a grid heater like your Workmaster has. Indirect injected diesels commonly have glow plugs as they are often more difficult to start when cold than a direct injected diesel. Direct injected diesels often do not have glow plugs but some like Hay Dude's Kubota do have them. I wonder if the Kubota uses glow plugs in that engine because of its unusually large cylinder size for a four-cylinder engine being hard to light off and run smoothly at first? He did mention the engine seems to be somewhat cold-blooded. 374 CID is huge for a four-cylinder engine, it's about a third larger than most other larger fours.

My VW TDIs (granted, NOT large 4cyl engines) are direct injection and they have GPs. GPs will run/operate for a bit of time after the engine has started in order to keep things smooth. I'd be surprised if more modern (my cars are circa 2000) diesel engines aren't likewise managed (it's also an emissions thing, so more and more likely so). I suspect that my NX5510 also runs GPs after startup. My 1993 generator has a small Kubota engine in it and I have to keepthe starter engaged even after it's fired up lest it die right away (GPs; no fancy circuitry).

BTW - IF that voltage out of the ECU was steady (somewhere in here is a solution, though not easy still probably less than $6k! ):

Controlling 12V with 0.5V signal

BUT... at 0.58V, IF this is a meaningful reading, it could be a bad wire (broken strands- one or a couple strands that are intact- amperage up [resistance from broken strands] and voltage down).

 

[Hay Dude]

My VW TDIs (granted, NOT large 4cyl engines) are direct injection and they have GPs. GPs will run/operate for a bit of time after the engine has started in order to keep things smooth. I'd be surprised if more modern (my cars are circa 2000) diesel engines aren't likewise managed (it's also an emissions thing, so more and more likely so). I suspect that my NX5510 also runs GPs after startup. My 1993 generator has a small Kubota engine in it and I have to keepthe starter engaged even after it's fired up lest it die right away (GPs; no fancy circuitry).

BTW - IF that voltage out of the ECU was steady (somewhere in here is a solution, though not easy still probably less than $6k! ):

Controlling 12V with 0.5V signal

BUT... at 0.58V, IF this is a meaningful reading, it could be a bad wire (broken strands- one or a couple strands that are intact- amperage up [resistance from broken strands] and voltage down).

That was my thinking, but took so much incoming and attacks for wanting to fix the original problem, (and of course the time it takes from trying to get actual work-work done) rather than “wiring up a switch” which is an easy-out 30 minute option of course.
I gave up chasing ghosts and sparks.
In a perfect world, removing the ECU and sending it out to be diagnosed would be my choice.
I have another development in symptoms of a possible bad ECU happen. The digital display on the right side console blows fuses randomly. Could be a sign of low voltage signal causing high resistance?

Since this whole thread blew up, I learned from a Messicks tech that Kubota ECU electronics is expensive and impossible to repair. Messicks had no other option than ECU replacement. They had another customer before me with deep pockets. He spent the $6000 on an M125x and everything was fixed. Their shop foreman also stated he sees more Kubota than the other brand they sell (NH) in for ECU issues. That did not sit well with me. Then again, they probably sell more Kubota, too. However, I think he was talking large frame farm tractors which NH is a bigger seller. Honestly, I don’t know what HP size tractor starts the need for an ECU, either.
There’s no opening of the Kubota ECU and repairing that they know of and no shops I would trust the ECU to sent for repair.
Other brands (New Holland) ARE sometimes repairable. May be others, but that’s their 2 tractor brands.

 

[Hay Dude]

Reviving topic for a moment…

So last week we were working in single digit to low double digit temps (aka “t-shirt weather”).
I arrived 6am in the morning to start the M-135X and as I rolled the key to the start position, the GP light came on!
>>>>just to catch up on what happened with the glow plugs, I wired up a spring loaded pretty heavy duty switch and it has worked well For the last 1-2 months. We couldnt spend any more time fiddling with the factory system<<<<<

Anyway, Im guessing somehow the dash cluster still reads the coolant and air temp sensors?
I have an almost twin to the M-135X (its an M-126X) and the GP light works at about 32* and lower. The M135X GP indicator light is now confirmed to be coming on at about 12-15*, much colder than the other.
I replaced the air and water coolant sensors, but they dont seem to want to activate current to the dash cluster until its much colder than the other tractor.

I dont think I have an ECM problem. I think theres something in the GP system not working correctly.

 

[ROUSTABOUT]

Get a push button starter switch and wire the glow plugs directly. Use them when you feel the need.

 

[Hay Dude]

Lol

From previous post #334
>>>just to catch up on what happened with the glow plugs, I wired up a spring loaded pretty heavy duty switch and it has worked well For the last 1-2 months. We couldnt spend any more time fiddling with the factory system<<<<<

 

[LouNY]

I wonder if you could obtain the resistance curve of the glow plug sensor, ohms to degree's.
Possibly an added on resistor would "calibrate" the system for an earlier turn on.

 

[IndyJay]

Lol

From previous post #334
>>>just to catch up on what happened with the glow plugs, I wired up a spring loaded pretty heavy duty switch and it has worked well For the last 1-2 months. We couldnt spend any more time fiddling with the factory system<<<<<

Finally!

 

[Hay Dude]

I wonder if you could obtain the resistance curve of the glow plug sensor, ohms to degree's.
Possibly an added on resistor would "calibrate" the system for an earlier turn on.

I was thinking defective batch of sensors (Water or air)?
Its getting close to spring and the really cold pretty much in the rear view mirror

 

[Hay Dude]

Finally!

I actually did it in early January. Its been working fine.