D1105 idles out of control

[Jim Leap]

I found this amazing thread while trouble shooting an idle issue with a Kubota 1105 diesel engine. Turns out my issue was identical to Kubix's issue. Don't know what I would have done had I not found this information. Sure didn't find anything else. At any rate I followed Kubix's solution - adjust "barrels" clockwise - to limit fuel flow. It worked! Simple solution to a seemingly rare and annoying problem. I feel like I found a "needle in a haystack". I don't think Kubota is aware of this issue. My local Kubota shop manager was clueless. I am so glad I didn't go to the expense of rebuilding the IP since that would not have solved the issue. No one had "tampered" with the barrel settings - the factory paint proved that. Thanks so much Kubix for sharing your trouble shooting adventure - you saved me a lot of headache.

Jim

 

[GodHungry777]

Hey Brains Trust.
I've got a similar issue on my D1105 (in KX41 excavator). It's a project I've just picked up and am steadily working my way through its issues.
The original problem I started chasing was bogging under load. Carrying out the work listed below (bottom) got me more revs (2500 max rpm prior - 3500rpm max revs now) but still bogs under load.
Also, if I reduce the throttle from full to idle, it takes about 20 seconds for the RPM to come down from 3000rpm to 1200rpm.
The injector pump barrels on mine were all set differently in terms of the twist adjustment described in the solution on this thread.
So I set them all the same (centred). The result was out of control rpm at idle.
So I adjusted them all 1mm clockwise. The result was good range and control of throttle from 1200-3000rpm.
BUT, still bogging under load - whatever working rpm I set the throttle to (2000-3000rpm), any load will drop it to 1500rpm.
EDIT: I just went and did a video to view the governor activity (

)
So to test it I have removed the throttle plate and set the throttle to 2000RPM. Then added the load on and off. The revs dropped to 1700RPM under load and I can't see any discernible movement of the governor lever (the upright lever in the middle) which should move the fuel slider on the injector pump to keep revs at 2000rpm. The lever does move on start up but not under load.
A slightly better video and angle of the governor not moving

QUESTIONS:
1. is there a recommended procedure/test for setting the injector pump barrel's twist adjustment or is it just trial and error?
2. Is my theory correct on how the governor lever in the video should work?
3. What are the possible causes? Sticky flyweight?

For reference, the following has been carried out:
- Fuel tank emptied, cleaned and refilled
- Fuel lines replaced
- Fuel filters replaced
- Fuel pump replaced
- Injector pump tested > OK
- Injectors tested > OK
- Air intake checked > All Clear
- Exhaust checked > All clear
- Oil and Oil Filter replaced
- Thermostat replaced
- Radiator flushed and refilled with coolant