JX90U Motor Issues *New to us tractor*

[2003Case]

Hello,

We have recently purchased a 2003 JX90U Case with a little under 1100 hours. The tractor has been having issues where the motor will hardly idle, then with a snap of the fingers it is running great and has all the power you need. Then as quickly as it started running well again, it will lose 80% of its power and not want to run or move. It just wants to die. Some times when I have the rpm's up higher and its running good they will just slowly start to drop and power will go away till I have to stop and let it struggle for a minute then its back up and running fine. I'm just starting my research into the issue, but with how fast the motor can switch back to running healthy, its almost as if there is a computer that keeps changing its mind how it should run. We have changed one of the fuel filters so far, but the other is quite the project to get to with the loader on so we have yet to do that. Is it a fuel issue we may be experiencing or is there possibly some electrical issues? When it is at idle the alternator is only producing about 10.6 V, but when it is revved up the alternator is producing good numbers.

Thank you in advance for any help or ideas on the issue!

 

[thepumpguysc]

That's a tuffy.. gonna take alittle diagnostic work to sort that out..
The alt. needs to put out more than 10v.. that's not good.. CHECK THE BELT.. make sure its tight & not just spinning on the pulley.
Check the battery.. gotta start w/ a good battery.
Your workin w/ the Iveco 3.9l engine correct??
That has a Bosch VE mechanical injection pump, yes?? SO no computer control.. all manual. unless theres a computer controlling the throttle movement.
START w/ making sure your getting full travel from your throttle.. With the engine off, move the throttle to WIDE OPEN/FULL THROTTLE & make sure it hits the stop screw on the injection pump.. IF NOT, adjust the linkage on the throttle rod.
Next.. when it goes to acting up> there is a lift pump on the other side of the engine.. it has a priming lever on it.. PUMP the lever while its acting up.. if the RPM's come back up while your working the lever.. you have a supply issue..
Those lift pumps are the weak point in the system.. NEW they're about 30-40.00
I think they can be cleaned also.. remove the top screw & clean the screen.. IF its full of crud, you KNOW you have a fuel quality issue..
Try all those & let us know how you made out.. Good luck & Merry Christmas.. TPG
& DONT FORGET the "hard to reach" filter..

 

[Sawyer Rob]

First thing I'd do, is to change all the fuel filters!

SR

 

[RickB]

Change the second fuel filter, it’s probably the primary filter and the one that’s plugged. Check the banjo fitting on the inlet side of the primary filter for debris. Clean the screen at the top of the fuel transfer pump for debris.

 

[RickB]

That's a tuffy.. gonna take alittle diagnostic work to sort that out..
The alt. needs to put out more than 10v.. that's not good.. CHECK THE BELT.. make sure its tight & not just spinning on the pulley.
Check the battery.. gotta start w/ a good battery.
Your workin w/ the Iveco 3.9l engine correct??
That has a Bosch VE mechanical injection pump, yes?? SO no computer control.. all manual. unless theres a computer controlling the throttle movement.
START w/ making sure your getting full travel from your throttle.. With the engine off, move the throttle to WIDE OPEN/FULL THROTTLE & make sure it hits the stop screw on the injection pump.. IF NOT, adjust the linkage on the throttle rod.
Next.. when it goes to acting up> there is a lift pump on the other side of the engine.. it has a priming lever on it.. PUMP the lever while its acting up.. if the RPM's come back up while your working the lever.. you have a supply issue..
Those lift pumps are the weak point in the system.. NEW they're about 30-40.00
I think they can be cleaned also.. remove the top screw & clean the screen.. IF its full of crud, you KNOW you have a fuel quality issue..
Try all those & let us know how you made out.. Good luck & Merry Christmas.. TPG
& DONT FORGET the "hard to reach" filter..

You’re a “pump guy” and the LAST thing you mention is the unchanged filter?

 

[2003Case]

Hey Everyone,

I just wanted to say thank you for all the input. I will make sure to get that second filter changed ASAP and I'll let you all know how it went.

Thank you!

 

[KWentling]

Did the problem start with this cold weather we're enjoying, or has this been ongoing? Sure sounds like a fuel issue, so filters for sure and if it's cold related you may be jelling or have ice in the fuel. Single digit above and below zero F temps here and I expect you are getting it too.

 

[2003Case]

It has been an on going issue, but it is made much worse on colder days. I agree fuel issue, I suppose I'm just surprised as to how it can just snap back to running fine and be good to go for a little if the filter is plugged that bad. I have tomorrow off so I think I'm going to pull it to the side of the house, start a fire for some warmth and go after that second filter. I'm personally new to tractors and hydraulics (which are some of the lines I need to remove for access) so hopefully it goes well. Really there isn't much in the way blocking access. My only issue is lack of experience with it all.

 

[KWentling]

That is kind of strange that it comes and goes. Maybe there is ice or debris in the tank that gets sucked up to the fuel outlet and partially blocks it?

 

[Sawyer Rob]

Is this a cab or open station tractor??

SR