Bad news big repair

[sallyb]

I have considered a direct wire to the glow plugs last year. It’s not a novel approach, but I believe when you disrupt the glow plug circuit it may derate the tractor.
Right now, the ECU is still reading the air and water temp sensors, but something else in the ECU circuit won’t turn them on. When I removed the water temp sensor plug from the water temp sensor in the glow plug wiring harness circuit, the tractor went into a derated mode.
What I think might happen is when the ECU sees the glow plug wiring circuit disrupted it will derate. I don’t know for sure.
I guess there’s only one way to find out…..
If I can fool the ECU into seeing both sensors, it may be possible, but I think any part of the harness not reading causes derate.

Do you know anyone who builds computers? If so have them look at ECU and see if they can identify problem.

 

[Hay Dude]

Do you know anyone who builds computers? If so have them look at ECU and see if they can identify problem.

I have identified a few and am contacting them at night when they are closed. AG Express unable to service Kubota electronics. Working long hours, so my time is limited.

Thanks for the calm suggestions. Maybe if someone goes to bed, we can get this solved!
Were headed back in the right direction.

 

[Skystream]

I have the shop manual for it of your interested in diagnosing.

 

[sallyb]

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?

There is a place in Dallas Texas that rebuilds ECU , I don’t remember the name , but I probably can find out, I have a 1988 f150 ford, one the first with ECU and it went out and my brother knew about company that rebuilds ECU, I remember we couldn’t find new one, I believe it cost me $100 and they programed it.

 

[Hay Dude]

I have the shop manual for it of your interested in diagnosing.

I already have it and went through the steps last year. Went through it again weeks ago, then Kubota dealer spent an hour or 2 testing it. I don’t claim to know everything like some and it needs fixed.
Maybe my corroded plug idea is the solution, I hope it is.

 

[DieselBound]

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.

Do you know that the light actually works? Yeah, perhaps a stupid question, but assumptions sometimes can cause problems...

 

[Henro]

I think it’s sad when someone asks for help, and people seem to try to help, and then it turns into bickering rather than staying focused on the issue.

For whatever reason. Could be unreasonable suggestions attempting to help, or rejection of reasonable suggestions by the original poster.

 

[Hay Dude]

Do you know that the light actually works? Yeah, perhaps a stupid question, but assumptions sometimes can cause problems...

No, I can’t prove it works. 2 years ago, the light would flicker, for a fraction of a second.
But even if the dash light was out, there’s no glow plugs whatsoever. Starting is rough.
My M126x (pretty much the same tractor, just 9 less HP) has glow plugs functioning properly and starts perfectly.

 

[Hay Dude]

I think it’s sad when someone asks for help, and people seem to try to help, and then it turns into bickering rather than staying focused on the issue.

For whatever reason. Could be unreasonable suggestions attempting to help, or rejection of reasonable suggestions by the original poster.

@Henro
Agree in general, but if that’s your accusation, could you find anywhere where I rejected anyone’s reasonable suggestions?
Heres my post on Saturday when the tread was started:

“So try to understand I’m trying to get the factory system working before I install a work around That’s my first preference. The purpose of the thread was to inquire if there’s anything else I may have overlooked to get the FACTORY system working.”

I’m trying to look for suggestions fix the Kubota OEM system first. If that’s not possible, install my own switch to energize the glow plugs. That’s easy. It can be done at anytime.
It’s that simple.
There have been at least a dozen suggestions for a block heater, too after it was stated there’s no AC power available.
I appreciate them, but after about the 20th bypass switch suggestion and about the 12th AC block heater suggestion, few paid attention to my desire to fix the original system???? More focus on insisting a one size fits all solution.
It gets a bit frustrating, but I’m staying positive!

 

[Alan46]

213 reply’s and counting.