See video explanation. Revs drop from 3000RPM to 1800RPM when any hydraulics are activated. Any thoughts? Here's what I've done so far: emptied and cleaned fuel tank (had water, rust and gunk) replaced fuel filters (clogged with water and gunk from tank) replaced fuel lines (lines were brittle) - had injector pump and injectors tested - tested ok bled injector lines replaced engine oil and oil filter replaced thermostat and coolant (thermostat was stuck open) air filter had already been replaced - exhaust is clear checked governor spring, forks and flyweight. Worn but nothing broken or missing cleaned and flushed hydraulic tank, replaced both filters (both filters were very clogged), filled with new oil.
Funny thing I also found your post on an orange tractor forum. The engine sure sounds lazy getting up to 3000. Are you sure that the start spring isn’t stretched or just weak? I would think an unloaded engine should spin up really fast, not slowly increase like yours is doing.
Good day It maybe that some of the fuel injection components have been damaged by that much stuff passing througth the sytem, I suggest begin by getting the injectors checked out. Kind regards Uffex
Injectors have been tested - OK.
Can't post in too many places can you Yeah this is what has had me chasing a fuel issue for the last month. I just can't see what I've left unchecked.
Good day That only the fuel pump left has that been bench tested? Kind regards Uffex
Fuel Pump or injector pump? Here's the fuel pump flow.
Good day I was refering to the injection pump Kind regards Uffex
Yeah, it's definitely pumping fuel out of the injectors but whether it's a restricted flow or not, I'm not sure. It's probably time to go deeper on it.
Update: Uncoupled Hydraulic Motor OK, I've uncoupled the hydraulic motor to remove any effect of the hydraulics on the revs. See video. In my introduction I say that uncoupling the motor had stabilised the revs but then my test on camera completely disproved that as the RPMs were all over the place. It still over-revs at even half throttle (WSM has Max Revs at 2400RPM) It still takes for ever to increase or decrease RPM when the throttle is adjusted. So, while we may still have a hydraulic issue, I think we need to sort out this unstable RPM issue first. Here's what I've done so far: emptied and cleaned fuel tank (had water, rust and gunk) replaced fuel filters (clogged with water and gunk from tank) replaced fuel lines (lines were brittle) - tested injector pump - pumping fuel evenly from all three pumps. Tested straight from outlets and through injectors. Tested fuel slider rail. Full and free movement. had injectors tested - tested ok bled injector lines replaced engine oil and oil filter replaced thermostat and coolant (thermostat was stuck open) air filter had already been replaced - exhaust is clear checked governor spring, forks and flyweight. Worn but nothing broken or missing. All free moving. cleaned and flushed hydraulic tank, replaced both filters (both filters were very clogged), filled with new oil.
Good day GH Your testing of the fuel injction pump will not show up faults under pressure, if you have a fuel speacialist you can use please take those components for proper testing on a bench. That gunk must have done some damage sorry if this is not what you like to hear. Kind regards Uffex
Attached may be of help. Kind regards Uffex
Excellent. Thanks for that.
My apologies to all for the delay. It has taken me forever to get hold of a Diesel Compression Tester with the adapters i needed. So to update: INJECTOR PUMP > I got the Injector Pump professionally rebuilt and calibrated by our local Bosch injector/pump specialist - no change to over revving, lack of power and bogging under load. COMPRESSION TEST > The manual says compression should be 412-469 PSI (Rebuild under 327 PSI) My results: Cylinder 1 - 380PSI Cylinder 2 - 410PSI Cylinder 3 - 320PSI So all are below operating range and one below rebuild indicator. Is low compression also going to cause the slow RPM response to throttle movement? Or are there still other issues (eg governor) that I'm dealing with for that?
Good day GH For sure it looks as though you have got trouble peering around the corner. I suggest that you take hold of the rack arm and feel if the governor is influencing the engine speed. If it is, it will mean going deeper into the motor. You could drain the sump and see if you get any clue from that end. Kind regards Uffex
I'm not a big fan of using a "cellulose" in line filter on a diesel. Not all paper ones are the same. Either get the correct Kubota one... Or, if 5/16" fuel line, use a Napa 3972. See if that helps.
FINAL UPDATE - PROBLEM SOLVED Ok. So after replacing the entire fuel system, the problem was where we first started - the governor flyweight sticking. NB. For future reference, see my earlier video of the engine running with the throttle plate off so the governor fingers are visible ( ). My original questions in pursuing the governor were to see if anyone knew if the movement of the governor fingers should be noticeable. I wasn't sure if the governor adjusting the throttle slide would be big enough to see it move if it was just making very minor adjustments to the slide. I would now suggest that if you don't see the fingers move under changing load conditions, you should head to the governor flyweight first. I have no regrets in replacing and repairing the entire fuel system along the way. Everything that was repaired or replaced was in terrible condition and I couldn't believe it was running at all in the condition they were in. Thank you to all for your input along the way. It's been a great education. Let me know if you have any questions about the process.