Grand L fel control adjustment maybe?

[droy]

Sorry for long post,
2013 cabbed 4740, HST+ with 1100+ hrs. Experiencing power loss, engine bogging & slow to recover especially when shredding.
I’m over the road O/O, wife mostly cuts pasture & had been complaining about power loss. Approx year back, two things happened when my job was really busy- algae in fuel, treated, drained tank, r&r fuel water filter (many times).
Also about the same time, one of the fel cables broke, replaced both but not adjusted correctly- have to carefully return control to neutral or it will load up engine a bit.
Yesterday before draining tank (again), I forced air through fuel line at filter, letting air agitate the fuel in tank then let it drain through hose & catching it before filter. Fuel looks good, no evidence of algae. When replacing old filter, I did notice a brown piece of something in filter bowl thought to be but not a leaf particle, approximately 3/16” x 3/16” not the algae sludge I previously encountered. Using a wet dry vac, vacuumed the empty tank- no trash.
Filled with fresh fuel, checked both air filters, cranked & did injector cut-out (loosen injector lines individually), same engine miss for each.
Engine did seem a tad bit more responsive but still sluggish. Using Stall guard, always did for some reason, it slows to a crawl when in some grass I feel it should zip through. Also sluggish moving dirt with fel & bb.
The engine doesn’t appear to have a miss, just feels like a 10 hp loss.
Wondering if improperly adjusted fel controls could be loading engine, (I do notice a difference when controls not fully in neutral) & irregardless would like to get it properly adjusted.
I’m only aware of the one fuel filter, loosened injector lines spraying good; did notice the “bleeder” line on injector pump partially open, closing it makes no difference in performance.
What am I missing? Valve adjustment? Any help / suggestions appreciated, & once again, if I someone knows the procedure to properly adjust the fel control cables, would be a big big help.
Thanks in advance & happy Father’s Day!!!

 

[JWR]

Can't really help much. I'm not understanding the FEL cables loading down the engine -- how does that happen? For one thing, what is a FEL cable?
With boat motors I have found that "enzyme type additive" often clears fuel issues I have not been able to clear other ways. With your history I would try one of the enzyme additives intended for biological contaminants. I use Star-tron Enzyme fuel treatment which is available on Amazon and other places. They also sell (same brand) a concentrate version of it specifically for diesel engines.

 

[droy]

Can't really help much. I'm not understanding the FEL cables loading down the engine -- how does that happen? For one thing, what is a FEL cable?
With boat motors I have found that "enzyme type additive" often clears fuel issues I have not been able to clear other ways. With your history I would try one of the enzyme additives intended for biological contaminants. I use Star-tron Enzyme fuel treatment which is available on Amazon and other places. They also sell (same brand) a concentrate version of it specifically for diesel engines.

Thanks for the reply JWR;
fel = front end loader. The cables resemble sleeved throttle cables, threaded on one end allowing adjustment to let the joystick control function properly.
Have been using Pen Ray brand of algae treatment which local heavy duty parts houses offer. Seems to work pretty good, as too big a dose will quickly cause the dead algae to plug a fuel filter. Will also look at the Star-tron brand as it seems that algae control has become a necessary way of life for most diesel engine owners.

 

[Hay Dude]

Had (2) similar issues recently.
One of my remotes for rear hydraulics was sticking, causing weakness in loader, but no engine power loss. You could hear a slight “hissssss” while it was stuck. Hydraulic oil got hot.

Had power loss similar to what you described. Removed M126X injectors and sent them to a Kubota approved diesel testing shop. 3 of 4 injectors failed. One that didnt was marginal.
Handed it over to dealer. Let dealer replace all 4 injectors. $7,000. Ouch.

 

[JWR]

You gotta be kidding -- injectors are THAT expensive ?

 

[npalen]

Something you might try to rule out hydraulic valve causing bypass over relief valve robbing horsepower: Put the tractor in a loaded condition such as going up a hill and then operate the loader up and down to see if power output changes significantly. I wouldn't think, however, that maxing out relief pressure would load the engine as much as you are describing.

 

[JWR]

Thanks for the reply JWR;
fel = front end loader. The cables resemble sleeved throttle cables, threaded on one end allowing adjustment to let the joystick control function properly.
Have been using Pen Ray brand of algae treatment which local heavy duty parts houses offer. Seems to work pretty good, as too big a dose will quickly cause the dead algae to plug a fuel filter. Will also look at the Star-tron brand as it seems that algae control has become a necessary way of life for most diesel engine owners.

Droy -- I knew what an FEL is, I just didn't know what an FEL cable was. You are talking about loader valve control cables from the joystick to the loader valve. Understand now.

 

[droy]

Had (2) similar issues recently.
One of my remotes for rear hydraulics was sticking, causing weakness in loader, but no engine power loss. You could hear a slight “hissssss” while it was stuck. Hydraulic oil got hot.

Had power loss similar to what you described. Removed M126X injectors and sent them to a Kubota approved diesel testing shop. 3 of 4 injectors failed. One that didnt was marginal.
Handed it over to dealer. Let dealer replace all 4 injectors. $7,000. Ouch.

Thanks Hay dude, suspecting an injector, but loosening lines one at the time produces a distinct miss which to me means the injector is working, perhaps not under load though. I may have to pull them & bring them in to be tested.
$7000 for injectors is a big OUCH imho!

 

[droy]

Something you might try to rule out hydraulic valve causing bypass over relief valve robbing horsepower: Put the tractor in a loaded condition such as going up a hill and then operate the loader up and down to see if power output changes significantly. I wouldn't think, however, that maxing out relief pressure would load the engine as much as you are describing.

Just traveling on flat ground & raising bucket will affect power, slowing engine speed.

 

[droy]

Droy -- I knew what an FEL is, I just didn't know what an FEL cable was. You are talking about loader valve control cables from the joystick to the loader valve. Understand now.

Correct, I should have used proper terminology.