Timing Fuel Injection Pump 2010 L3940

[defdeskubota]

A few years back I was having a great deal of difficulty purging the air out of the fuel line to get restarted after a service. After killing the battery, I went on YouTube to troubleshoot and found out about cracking an injector to let the air out the top of the system. Upon doing so , tractor ran like hell, lots of black smoke and down on power. I brought it to my local dealer who said I had messed with the pumps timing by doing so and that it was $$$ to fix. He said in lieu of that, he could put it on the dyno and spin the injector to get it close to timing by ear.
I've been running like that since, but his dyno figures said it was still down a few horses and it still makes a bit of black smoke.
Is this really a $3K fix to make right?

 

[85Hokie]

" cracking an injector " does not change the mechanical timing of the the injector pump - it simply allows "air/fuel" to spill out under high pressure. Seen it done many times to bleed air from fuel lines.

I think the "down on HP" could be somewhat related to a "clogged" injector rather than a messed up pump.

Before I would EVEN consider throwing money into that engine - I would check compression, if that is is ok -possibility cleaning or replacing injectors themselves.

I think your dealer is full of shyte!

 

[hagrid]

If you cracked the lines on top of the injector to purge air then you didn't do anything wrong.

If you cracked the lines coming out of the pump and inadvertently disturbed the index of the plunger sleeves then you did something expensive.

 

[D2Cat]

Hokie and Hagrid are right on. The only way you change the timing is to remove the injection pump and change the number of shims that are under it!!!!!!!

Find a new tech, but read your owner's manual and you'll discover how to bleed air from you tractor.

 

[defdeskubota]

If you cracked the lines coming out of the pump and inadvertently disturbed the index of the plunger sleeves then you did something expensive.

From what I recall, as I tried to open the nut holding the fuel line, the part below (injector?) spun a bit until I held it with a second wrench. That's why when the service manager said he spun it back until he got the best power figure it made sense to me.
Sorry I'm a bit vague, but this was many years ago.

On the suggestion of dirty/ bad injectors, what kind of fuel additives do you run for cleaning?
I have taken to Sea Foam on my 7.3 Powerstroke.

 

[North Idaho Wolfman]

WOW... Who ever you took it to scammed the living snot out of you!
And trust me I'm being kind!
Not blaming you, blaming the place you took it to.
I've been doing this for quite a few years and I've never seen or heard of someone putting a tractor on a dyno to set the timing!
Places and mechanics like this make me sad to be called a mechanic!

No amount of messing with the input fuel lines will effect the timing or do any damage to the pump.
Fuel feed line in yellow.
You will note that this model has locks on the fuel delivery valves and even unlocking and turning those is a simple fix, pull the pump and rebuild it, reinstall and done, less than a $1k bill overall.

You don't use snake oil injection cleaners to clean the injection system on these!
Remove and replace all 4 injectors with new or good rebuilt injectors.
Simple job that only takes about an hour.

Remove all injector lines (RED)
Remove all overflow return lines and fittings (BLUE)
Remove injectors and seats (Green)
Reverse the prosses to finish it.
Leave all 4 lines loose at the injector side, crank till fuel is present, tighten lines.
Go enjoy running your tractor

You have all of us to help you out along the way, just ask!

 

[Henro]

WOW... Who ever you took it to scammed the living snot out of you!
And trust me I'm being kind!
Not blaming you, blaming the place you took it to.
I've been doing this for quite a few years and I've never seen or heard of someone putting a tractor on a dyno to set the timing!
Places and mechanics like this make me sad to be called a mechanic!

No amount of messing with the input fuel lines will effect the timing or do any damage to the pump.
Fuel feed line in yellow.
You will note that this model has locks on the fuel delivery valves and even unlocking and turning those is a simple fix, pull the pump and rebuild it, reinstall and done, less than a $1k bill overall.

View attachment 92523

You don't use snake oil injection cleaners to clean the injection system on these!
Remove and replace all 4 injectors with new or good rebuilt injectors.
Simple job that only takes about an hour.

Remove all injector lines (RED)
Remove all overflow return lines and fittings (BLUE)
Remove injectors and seats (Green)
Reverse the prosses to finish it.
Leave all 4 lines loose at the injector side, crank till fuel is present, tighten lines.
Go enjoy running your tractor

You have all of us to help you out along the way, just ask!

View attachment 92524

Being someone who doesn't know anything, I have to ask this question.

Isn't what Hagrid said true?

I remember reading and being convinced never to loosen the lines to the injectors at the injector pump end. OR IF YOU DO, use two wrenches and hold the important side in position, and loosen the side that loosens the line going to the injector.

Like I said, maybe I don't understand. But if what Hagrid said is correct, then it kind of makes sense what the mechanic the OP took his tractor to tried to do...not perfect obviously, but apparently the tractor runs better than it did before the attempted reajustment was done.

Just seems like it was a reasonable half "baked" attempt to improve things. (We use a different word than bake locally )

 

[North Idaho Wolfman]

Being someone who doesn't know anything, I have to ask this question.

Isn't what Hagrid said true?

Yes it can happen on a lot of models of injection pumps.
On this model it would take quite a bit of doing to turn them, as it has locks on the injection pump delivery valves to cut out the inadvertent movement issue.
Also even if you do turn the delivery valve holders it doesn't take a lot to fix it, you just send the pump to be rebuilt, that fixes all the issues in one quick step, and it's also not super expensive either.

 

[007kubotaguy]

I am with Wolfman. This is so sad. I just fixed a L S tractor that uses the same type of injection pump as the Kubota. The lady ran it out of fuel. Service guy came to get it started. Two weeks later and a $1000. 00 he walked away. He got it started but now has no power. Complete service, all new rubber fuel lines , fuel lift pump, tons of fuel cleaner. Told the lady it was out of time. This tractor had 125 hours on it. I could see the lines had been losed on top of the injection pump. Checked the tightest of the delivery valves. Number 3 lose as can be. Tighten it tractor runs like new. Less then 5 minutes on site. Lady not happy. I would have a coversation with your mechanic.

 

[Henro]

Yes it can happen on a lot of models of injection pumps.
On this model it would take quite a bit of doing to turn them, as it has locks on the injection pump delivery valves to cut out the inadvertent movement issue.
Also even if you do turn the delivery valve holders it doesn't take a lot to fix it, you just send the pump to be rebuilt, that fixes all the issues in one quick step, and it's also not super expensive either.

Got it. I think the message is NEVER loosen the lines at the injector pump if you are not absolutely sure of what you are doing. My plan anyway…

 

[North Idaho Wolfman]

Got it. I think the message is NEVER loosen the lines at the injector pump if you are not absolutely sure of what you are doing. My plan anyway…

Yes that's one way to look at it!
Or come on here and several of us can walk you through it properly!

 

[North Idaho Wolfman]

I hope defdeskubota you don't think we are picking on you, not at all.
We have all gotten a bad wrap on one thing or another over the years!

 

[lugbolt]

Being someone who doesn't know anything, I have to ask this question.

Isn't what Hagrid said true?

yes. I've done it myself.

 

[defdeskubota]

I hope defdeskubota you don't think we are picking on you, not at all.
We have all gotten a bad wrap on one thing or another over the years!

No not at all, I'm happy to have answers to questions that I've had in my head for 4-5 years.
In the not so strong defense of the tech at Pinnacle View Kubota in Walpole NH, he did say the pump needed to be removed and rebuilt to fully fix the problem. He also said that that would cost 3K+ to to do. The fix that they did to get it running as it has been since then was about $700 as far as I can remember. When I brought it in, it barely ran with lots of smoke and zero power.

 

[defdeskubota]

Just to be clear, as I think was incorrect in my nomenclature, I cracked the red fittings below and inadvertently spun the yellow fittings.

 

[hagrid]

That explains why your tractor was burping and farting.

 

[fried1765]

WOW... Who ever you took it to scammed the living snot out of you!
And trust me I'm being kind!
Not blaming you, blaming the place you took it to.
I've been doing this for quite a few years and I've never seen or heard of someone putting a tractor on a dyno to set the timing!
Places and mechanics like this make me sad to be called a mechanic!

No amount of messing with the input fuel lines will effect the timing or do any damage to the pump.
Fuel feed line in yellow.
You will note that this model has locks on the fuel delivery valves and even unlocking and turning those is a simple fix, pull the pump and rebuild it, reinstall and done, less than a $1k bill overall.

View attachment 92523

You don't use snake oil injection cleaners to clean the injection system on these!
Remove and replace all 4 injectors with new or good rebuilt injectors.
Simple job that only takes about an hour.

Remove all injector lines (RED)
Remove all overflow return lines and fittings (BLUE)
Remove injectors and seats (Green)
Reverse the prosses to finish it.
Leave all 4 lines loose at the injector side, crank till fuel is present, tighten lines.
Go enjoy running your tractor

You have all of us to help you out along the way, just ask!

View attachment 92524

You provide immeasurable help!
Sainthood may be in your future!

 

[North Idaho Wolfman]

Just to be clear, as I think was incorrect in my nomenclature, I cracked the red fittings below and inadvertently spun the yellow fittings. View attachment 92567

Yes that's bad, but there should be locks on them to stop that, but it wouldn't be the first time I've seen the locks loose enough to turn them.

 

[defdeskubota]

Yes that's bad, but there should be locks on them to stop that, but it wouldn't be the first time I've seen the locks loose enough to turn them.

Well one definitely did turn, soooooo, were it you, how would you proceed? Is it more cost effective to get a new pump, or fix what's going on with what I have? Tractor has close to 1000 hours in it.