Bad news big repair

[Hay Dude]

Did I mention there no glow plug light on dash cluster? It’s not a dummy light. I don’t think it’ll glow unless glow plugs glow.

 

[Hay Dude]

I think mine is 35, but not positive.
It doesn’t work at any temperature anyway

 

[Paystar]

Somewhere along my learning curve I remember Ether/Gas - OK, Ether/Diesel - no-no.
But I have been successful with WD-40 on diesels. I've one Ford 7.3 that I uses it on annually.

That's why I have used this in the past on the older big trucks. It has a lubricant in it.

https://www.kleenflo.com/products/730.html

 

[newbury]

That's why I have used this in the past on the older big trucks. It has a lubricant in it.

https://www.kleenflo.com/products/730.html

That is nice but I only use about 20 squirts of WD40 per year at the most, and I buy WD40 by the case every few years when it goes on sale. Down in Mississippi I use a lot of Water Displacement formula 40 for rust prevention on exposed metal, that and sheep lanolin (Fluid Film and Woolwax) comprise my main ammunition against rust.
I have not tried Fluid Film for a starting fluid but I don't think it would work well

 

[WranglerX]

I use "cheap" carburetor cleaner on some of my gas engines (very stubborn B&S twin in mower) its less volatile than ether based fluids there for less explosive in firing, but does well... Not sure how it would respond in diesels as my tractor does have functioning GP's....

 

[nightowl490]

Purchased my M135X in warmer months almost 3 years ago (April 2019). Never thought to see if the glow plugs worked. They actually won’t work if it’s over 41*.
Last winter, I realized the glow plugs weren’t working. Ohmed out wires, looked at wiring for mice damage, water damage, bad grounds, etc. Ohmed out wiring. Thats when I learned the glow plug system in larger kubotas is more complex than I thought. All 4 glow plugs passed electrical testing.
The glow plugs have 2 sensors one for air temp, one for water temp. The ignition switch is also part of the circuit. Then there are 2 relays and a fuse. All of this is controlled by the ECU. Last winter, I replaced
Key switch
water temp sensor
air temp sensor
both relays
fuse

Still no glow plugs. With nothing left to replace or test, I succumbed to a very reputable Kubota dealer. They basically did all the same things I did and replaced one of the new sensors I had already placed.
Still nothing. They called Kubotas double secret probation hotline and Kubota thinks it’s the ECU.

ECU price $6000
ECU Not returnable and no guarantee it will fix glow plugs.

So I’m out of answers. Any thoughts on other possible avenues to pursue?

Unless your absolutely sick over it not working properly (In the tune of $6k Sick...). $50 Katz Block Heater...... Problem solved.

 

[stso9d]

$6000 versus a hard wire... I sure don't need to spend much time on that decision....

 

[Unhitched]

to overcome the the ECU derating the motor because the sensors are derated the easiest way would be to find a used glow plug and plug it into the ECU while the glow plug that is actually in the motor is run off a manual switch, if you were really tricky you could figure out what the resistance of the sensor is and just wire in the a resistor so the computer thinks there is a glow plug there. me I would just find another glow plug and it in, actually I would just suck it up and pay for the ECU, or just keep running it the way it is, maybe put a block heater in it to help out on the cold days.

 

[RichNJKubota]

Did you ohm out all the wires back to the ECU connector? I think you mentioned looking for corrosion on the ECU connector?
I work on old cars and I frequently have to ohm out wiring back to the ECU. Between the ECU and a sensor there may be an intermediate connector. Most connectors these days have rubber seals so water can't get into the connector. But I've seen where the rubber seal has failed, water gets in and the connection is not good. Even though the outside of the connector can look new.
Disconnect the battery and ohm out the circuits. If you find corrosion use an appropriately sized jewelers screwdriver or other tool to carefully clean the contacts. Spray electrical contact cleaner also works well. Some of these contact cleaners will leave a slight oil film which will help in stopping future corrosion.
If you should decide to manually control the glow plugs I suggest you totally isolate the glow plug circuit from the ECU so that the ECU does not get damaged in any way. But I would really recommend fixing it correctly. I rarely ever see a bad ECU in the cars I work on.

 

[Alabastershame]

Seems like you could tie into the pos. Feed to the first relay to a solenoid. Tie into the outgoing of the last relay for the other solenoid post. Activated with a push button from cab. I dont see how the computer would be affected as all the factory wiring would remain in place and the addons would be piggybacked. I would try it.