How to start diagnosing crank-no-start on a kubota common rail diesel

[PoTreeBoy]

This is very weird indeed. The battery is pretty new and shows 12.8V. My charger is 30amp and runs at ~14 volts. The battery has no trouble running the starter alone. However, it will only start if I have the charger on and it starts right up, on the first crank. I am thinking that the slightly higher voltage 14 vs. 12.8 is the key

This is coming from left field, but are you maybe wiggling a power wire from the battery clamp when you connect the charger clips? Have you tried starting it with the charger connected but turned off/unplugged?

You wouldn't happen to have a schematic? Since this is a stationary installation, it might be significantly different from a tractor.

 

[whitetiger]

focus on whatever STOPS the engine from running when you turn key to 'off'.

The ECU removes the ground from the injectors.

 

[hodge]

I've checked it last night. It gives great cranking current - over 300 rmp. I think there is no easy solution here, I will need to read the manual and start diagnosing step by step

I know that on automobiles, if the voltage drops below 11.2 or something like that while starting, it will affect the electronics.

 

[lugbolt]

you need to be able to see the fuel rail pressure to eliminate that part of the equation. IOW, on the tractors, if you are hooked up to diagmaster and can log rail pressure while in a crank/no start condition, a lot of times you can see rail pressure rise and drop for each injector's opening. If an injector is stuck closed, you'll see a normal rise and fall for the rest of the injectors and a big spike and no or little fall for the one that is not opening. Or if one is bypassing too much, no or not enough rise. Also need to see SCV voltage among other things to know if it's doing it's job.

Sadly without being able to see that stuff, it's just gambling and possibly throwing parts at it. And firing the parts canon gets real expensive real quick.

 

[InTheWoods]

I checked my charger and it is rated for up to 50 amp. So I am pretty sure that the voltage remains stable.

No. If your starter is pulling 300A, as you say, your battery voltage is NOT 'remaining stable'.

 

[c5vettster]

Ok, I did the injector byflow test. I think the results are fairly conclusive. Two of the injectors are dumping all the fuel back, while one is doing ok. I am ordering a set of three injectors from amazon. Should be here on monday

 

[c5vettster]

you need to be able to see the fuel rail pressure to eliminate that part of the equation. IOW, on the tractors, if you are hooked up to diagmaster and can log rail pressure while in a crank/no start condition, a lot of times you can see rail pressure rise and drop for each injector's opening. If an injector is stuck closed, you'll see a normal rise and fall for the rest of the injectors and a big spike and no or little fall for the one that is not opening. Or if one is bypassing too much, no or not enough rise. Also need to see SCV voltage among other things to know if it's doing it's job.

Sadly without being able to see that stuff, it's just gambling and possibly throwing parts at it. And firing the parts canon gets real expensive real quick.

What is the diagmaster and where can I get it.
So I think the diagnostic system in the controller is working. I tried to start the machine with the injection pump solenoid disconnected and it triggered a code right away.

 

[North Idaho Wolfman]

What is the diagmaster and where can I get it.
So I think the diagnostic system in the controller is working. I tried to start the machine with the injection pump solenoid disconnected and it triggered a code right away.

Only a Kubota dealer has a Digimaster, and if you replace injectors you will need the new injectors programed into the ECU.

 

[c5vettster]

Only a Kubota dealer has a Digimaster, and if you replace injectors you will need the new injectors programed into the ECU.

How do you program them? Do you have to calibrate them using special stand?

 

[TheOldHokie]

How do you program them? Do you have to calibrate them using special stand?

I believe the calibration data is stamped on the injectors. The calibration data is programmed BY THE DEALER using Diagmaster software and hardware interface.

Dan

 

[c5vettster]

I believe the calibration data is stamped on the injectors. The calibration data is programmed BY THE DEALER using Diagmaster software and hardware interface.

Dan

Thanks Dan,
I am buying aftermarket injectors. Do you think they will have the stamping required for this process?

 

[TheOldHokie]

Thanks Dan,
I am buying aftermarket injectors. Do you think they will have the stamping required for this process?

I am no expert but if they are made for this application I would think so. Maybe the bigger quedtion is will your dealer use them.

Dan

 

[Hugo Habicht]

I know that on automobiles, if the voltage drops below 11.2 or something like that while starting, it will affect the electronics.

When cranking in cold conditions the battery voltage drops way below this value. The vehicle electronics has to be designed to handle this. Volkswagen for example specifies a drop to 3V at cold crank. Other manufacturers have their own specifications but they are all similar.

 

[Hugo Habicht]

Sorry, my memory failed me there. The severe cold start voltage is 3.2V and during a normal start the electronics has to work with voltage drops down to 4.5V. See attached diagram from the LV 124 specification that most car manufacturers adhere to. I would not know what Kubota requirements are though.

With load dump voltages of up to 150V for about 1/2 second when you disconnect the battery while engine running and all kinds of short voltage spikes from -400 to +400V you find in a typical 12V automotive environment supplying a microcontroller with steady 3.3V is not trivial. I struggled when I had to do that in a former life

 

[Russell King]

The OP stated this in post #1:
“I have a strangely behaving Kubota D1803-T diesel in an air compressor.”

Does a Kubota engine need diagmaster in any equipment or would that equipment vendor have their own control system? I assume that the ECU could be by Kubota and that the engine is what the ECU is connected to but I am just curious about how it works with other vendors using Kubota engines.

 

[TheOldHokie]

The OP stated this in post #1:
“I have a strangely behaving Kubota D1803-T diesel in an air compressor.”

Does a Kubota engine need diagmaster in any equipment or would that equipment vendor have their own control system? I assume that the ECU could be by Kubota and that is what the ECU is connected to but I am just curious about how it works with other vendors using Kubota engines.

Most (all?? ) third parties use Kubota's engine management hardware and software and they are the community that buys Diagmaster licenses.

Much of what Kubota uses comes from Denso..

Dan

 

[c5vettster]

The OP stated this in post #1:
“I have a strangely behaving Kubota D1803-T diesel in an air compressor.”

Does a Kubota engine need diagmaster in any equipment or would that equipment vendor have their own control system? I assume that the ECU could be by Kubota and that the engine is what the ECU is connected to but I am just curious about how it works with other vendors using Kubota engines.

The compressor has its own controller which can read the ECU error messages. However, I think the ECU is from kubota.

 

[ruger1980]

As stated you will have to have Diagmaster to program the injector trim codes in the ECM. It will run without programming the new codes but the flow calibration will be off by a small degree.

If the engine is in an air compressor then it should be an industrial engine. You will have to find a service provider with that license. My experience is that most ag dealers cannot or will not service industrial engines.

The company I work for uses some Kubota built/branded engines and they all have to have an industrial dealer perform any warranty or service repairs on them. We also have engines that are built by Kubota and branded by our company. They are serviced by our own diagnostics platform and they cannot be accessed via Diagmaster.

I know Takeuchi has an agreement with Kubota for the engines they use and their license allows them to communicate with engines used in their machines but not other brands. I am not sure if an industrial dealer can connect and communicate with their machines.

 

[TheOldHokie]

As stated you will have to have Diagmaster to program the injector trim codes in the ECM. It will run without programming the new codes but the flow calibration will be off by a small degree.

If the engine is in an air compressor then it should be an industrial engine. You will have to find a service provider with that license. My experience is that most ag dealers cannot or will not service industrial engines.

The company I work for uses some Kubota built/branded engines and they all have to have an industrial dealer perform any warranty or service repairs on them. We also have engines that are built by Kubota and branded by our company. They are serviced by our own diagnostics platform and they cannot be accessed via Diagmaster.

I know Takeuchi has an agreement with Kubota for the engines they use and their license allows them to communicate with engines used in their machines but not other brands. I am not sure if an industrial dealer can connect and communicate with their machines.

My understanding is there is a Takeuchi specific version of Diagmaster and its licensed and used by industrial service providers. Hacked copies are readily available on line.

Dan

 

[whitetiger]

My understanding is there is a Takeuchi specific version of Diagmaster and its licensed and used by industrial service providers. Hacked copies are readily available on line.

Takeuchi owns the right to the Kubota engines they use, so they have their own ECU and diagnostics. A Kubota dealer or Kubota industrial engine service center can not connect to them.

Takeuchi owns its engines, which are different from any others Kubota manufactures. The warranty and software are all Takeuchi's.

Their diagnostic port is also different from what Kubota Tractor and Kubota Industrial use.

.