Grand L5030 starts/idles perfectly but chokes when loaded.

[texasjohn]

I'm looking for ideas to try a fix.

I used the tractor for a couple of hours with a drag disk turning over the ground with no problems. All was working dandy until symptoms developed suddenly during this operation. Disk has been removed, symptoms remain.

symptoms:
Grand L5030 with nearly 1000 hours starts easily
idles perfectly, running smoothly
throttle lever will perfectly increase RPM's smoothly and quickly from idle to 3000 or more, no problem even when throttle is very rapidly moved from idle to high RPM'S.
HST transmission pedal will move tractor forward as long as only very slow speed is requested. This is true for L or M or H range. At an early point, if pedal is depressed much, the engine chokes down, slows, almost dies. This is true at any initial RPM "no load" speed, including 3000 RPM. However, backing off of HST quickly results in fast recovery of RPM's to the "no load" speed.

working hypothesis: seems that under load (simply moving tractor at much speed with no implements attached) insufficient fuel is being delivered to maintain RPM's thus RPMs drop rapidly

Trouble shooting completed:
Air filter checked, perfect shape, no dust, no restrictions.
fuel filter bowl cleaned and filter replaced (twice), although no problem found
gravity fuel flow into fuel bowl is sufficient/unrestricted.
Complete grease, fluids, filter service done personally about 6 hours before problem appeared. All fluids double checked and full, no change since service.
Diesel fuel all from same tank, several hours used before problem appeared.
Physical link between HST pedal and transmission is unrestricted and operates smoothly.

I have work shop manual. Assuming there a is fuel restriction, the next thing beyond the filter is the fuel pump, then the injection system. These are items for the dealer to look into and that is my next step unless someone has an idea of something else to try.

Anybody have any other ideas??

[art]

You used the words chokes down does that mean that it is smoking when it is dying?

[ibnxe]

Your symptoms sure sound like a fuel delivery issue. I am not familuar with your model, but would carefully check that you are getting enough fuel flow to the injection pump. My tractor has two fuel filters, one before and the other after the fuel pump. The suction side filter plugged up and I had the same result as you have described.

[Fordman1981]

I agree that it's probably fuel related we have a skid steer at work was doing the very things you described. Turns out ours was a fuel pump it had a 3 and a half psi pump once they get age on them they deliver 2 psi or less so they put a 10 psi pump on ours and several others that had done the same thing.

[David_Kb7uns]

If things do not check out with fuel issues, read this thread and see if it is similar to your problem.
http://www.tractorbynet.com/forums/k...inute-max.html

Have heard of govenor springs going before.

David Kb7uns

[texasjohn]

Art, no smoke when dying. The power loss is instantaneous and return to full RPMs takes less than a second when the load is removed.

Thanks for replies, am now going to read thread suggested.

[Tx Jim]

Do you happen to have the parking brake applied???????

[art]

Art, no smoke when dying. The power loss is instantaneous and return to full RPMs takes less than a second when the load is removed.

Two different problems! I'd think you still could have a fuel blockage problem even starting back at the tank!

[DDM84]

Two things I would check. 1 - check the fuel bowl. I don't remember which fuel bowl is on your model but check to make sure the o-ring around the top of the fuel bowl present. I've had a customer with similar symptoms that was missing the o-ring after he serviced his machine and it was sucking air. Also make sure there is a spring under the filter element in the bowl and an o-ring on the pipe that the fuel filter slides over. 2 - check the brake linkage. If a rod has been bent and engaging the brake you may be powering through the brake. Let us know what you find and good luck.

[slowzuki]

Brake won't cause die off. Its fuel or governor related. Was your air bleed screw left open after the fuel filter change?

When I remove my fuel filter, if the fuel is not turned off at the lever, it blasts out all over place.