Resolved!. Really need some help, Kubota dealer stuck, 2024 RTV520h engine issues
- Thread starter omextreme
- Start date
The dealer does not have an exhaust gas analyser? They should have one in order to repair petrol engines.
Is it a fully programmable ECU? In this case you should be able to correct the fuel / air mix at low revs.
Another thing: in my experience 98% of petrol engine problems come from the ignition. I know you changed the ignition sensor, but has the ignition timing and dwell angle been checked over the full speed range?
And you wrote 2024, so pretty new, so it may not be applicable. For older cars the spare parts are often of substandard quality. Distributor caps are garbage those days and I spent 3 days looking at fuel problems when it turned out to be a faulty spark plug (was brand new, reputable manufacturer). The symptoms were exactly the way you describe them, bad at low revs and fine at high revs.
Another thing: in my experience 98% of petrol engine problems come from the ignition. I know you changed the ignition sensor, but has the ignition timing and dwell angle been checked over the full speed range?
And you wrote 2024, so pretty new, so it may not be applicable. For older cars the spare parts are often of substandard quality. Distributor caps are garbage those days and I spent 3 days looking at fuel problems when it turned out to be a faulty spark plug (was brand new, reputable manufacturer). The symptoms were exactly the way you describe them, bad at low revs and fine at high revs.
I don't know about the customization side of the ECU, I know Kubota sent over a "profile" to load onto the ECU.
I don't know what's wrong with the engine, but I know that dealer is using the mud technique. Throw stuff at it and hope it sticks. They have no clue what they are doing.
Bad at lower RPMs and good at higher RPMs? Anybody look at sensors?
Bad at lower RPMs and good at higher RPMs? Anybody look at sensors?
That dealership sounds terrible. Just load the parts cannon.
I haven’t looked at the wiring diagram for that model but I’ll go with a simple one. Does it have a seatbelt interlock? To restrict speed if the seatbelt isn’t fastened?
I haven’t looked at the wiring diagram for that model but I’ll go with a simple one. Does it have a seatbelt interlock? To restrict speed if the seatbelt isn’t fastened?
You need someone who knows how to use a scope and check the signal from the crank position sensor,
cam sensor, injectors and ignition. Did they confirm the crank/cam timing is correct.
They should be able use their scan tool and check the the o2 sensor voltage.
This is a simple engine it should not be that hard to find the issue.
cam sensor, injectors and ignition. Did they confirm the crank/cam timing is correct.
They should be able use their scan tool and check the the o2 sensor voltage.
This is a simple engine it should not be that hard to find the issue.
I agree, I assumed that taking it to the Kubota dealer was my best bet. I don't have many options nearby and the Polaris / buggy guy near me doesn't work on Kubotas
Re read this again and found your posts on other forums(same user name). This machine has been damaged in a fire?
Your post on another form you state “every once in a while smooth acceleration bottom to top. Hot or cold same outcome”.
So the problem is not consistent?
Your post on another form you state “every once in a while smooth acceleration bottom to top. Hot or cold same outcome”.
So the problem is not consistent?
Yes this unit sustained damage to the front right from being near a fire, not on fire. Absolutely no heat damage to engine or wiring (aside from the ignition key)
For the first day we had brief periods of smooth accel. After running a few miles the "good throttle" went away and never returned. This is why I took it in the acceleration issues became constant.
Final update, this thread.
Dealer "found" a broken wire or mostly broken wire engine runs like a champ now..
BUT now its dead again. Transmission? Starting new thread.
Dealer "found" a broken wire or mostly broken wire engine runs like a champ now..
BUT now its dead again. Transmission? Starting new thread.
Runs With Scissors
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Glad you got it fixed! 
But just for future reference, what/which wire was broken?
It might help someone in the future
But just for future reference, what/which wire was broken?
It might help someone in the future
I honestly cant find a repaired wire... SO a bit of a mystery. Ill look more and let you know what i find.Glad you got it fixed!
But just for future reference, what/which wire was broken?
It might help someone in the future