Power Loss, no smoke

[jremmons]

Hey all,
The past couple weeks our 6220 Deere w/ PowrQuad Plus transmission has been experiencing what I would call a loss of power under load, e.g. when driving up small hills in road gear, the RPMS will start to pull down below 2000 and speed will keep reducing until it returns to flat ground; similarly, when out spraying in a field if I do a hard brake (w/ brakes unlocked) to reduce turning radius, it will very nearly kill the tractor until I remove my foot from the brake at which point the RPMS will very slowly creep back up and the engine will start returning to speed. The final symptom is that if trying to start from a dead stop (e.g. a stop sign) in the lowest 'road' gear (D1 for our tractor), it almost seems as if the tractor wants to die; if we start form a dead stop in a lower range/gear, e.g. C1, it will still be a bit rough but easy enough and then as it's rolling you can start shifting up gears and ranges. We've never had this issue with the tractor before. Once getting the tractor into the top 'road gear' (D4 for us), it will still not hit its previous top speed/RPM and any minor incline will slow it 1-2mph.
The tractor starts up just fine and does not blow out much/any smoke when starting and nothing when rolling down the road.
I have bled off what water/gunk I could from the tanks and filter and replaced the fuel filter, with no improvement. I have also checked/cleaned both engine air filters, which were replaced this past Winter (and normally last anywhere from 1000-1500 hrs). I also added some of John Deere's 'diesel fuel cleaner' type additive, with no apparent effect.

This 'power loss' was fairly sudden and happened when we were out mowing access lanes and became more noticeable when spraying.

Thanks for any advice and as this is my first post, if this is in the wrong forum please direct me where I need to stick it instead.

 

[3Lfarms]

90 hp is a larger tractor than what most people on TBN have, but I’m sure someone with some experience on larger JDs will be along.

How many hours are on this tractor?
No smoke would seem to indicate the turbo is working. A compression check would be a good start. If that checks out, I’d be looking at the injection pump and injectors.

 

[searcyfarms]

does the tractor sit much, do the tanks you use to fill it sit outdoors and store fuel and sit for a while? i have had this with 3 units over the winter, all had algea/slime in the fuel system reducing the fuel distribution. They were my buddies White 2-105 Farm Boss, Kubota B2200 ( neighbor ) and John Deere 510 Backhoe ( neighbor ) all from low sulfur diesel and sitting over the winter and long periods not being used. My buddy uses a transfer tank and it sits a lot too so had it in there also. Removed the sediment bowl assembly on the White, rinsed with clean fuel as best we could, removed fuel line on kubota and deere, just pulled line loose on the tanks running to the filter on the deere and then removed line assembly, get as big of a hole out of the bottom of the tank because when the stuff comes out it will be slimy chunks. Get extra fuel filters as you wont be able to get it all out. Run some sort of algae killer in with your new fresh fuel, it will continue to break down stuff in the tank and likely you might have to redrain or replace filters a couple times before it all clears up. Never used to have this with old diesel fuel due to the higher sulfur content but its a known menace now.

good luck, its frustrating as heck!!!!!

 

[powerscol]

Well - it is an indiction of and injector pump going bad, but could be a plugged fuel filter or weak lift pump (pump that delivers fuel from filter at about 5 to 8psi to injector pump). Power loss usually is caused by lack of fuel, so start with the easy stuff fuel filter, line from tank, lift pump pressure. Does your JD have any built in diagnostics?

Hope this helps.

 

[kthompson]

My JD5525 couple of years back did about the exact same thing. Turned out fuel filter was catching air. I did have to pump the air out of the fuel system though. Also could be a piece of trash in the fuel tank. Think the way I found my issue was finally unscrewed the fuel filter to see if fuel was getting to it. Have you tried to find if fuel was getting to the fuel filter when this happens?

 

[thepumpguysc]

That inj. pump is an electronic pump/fly by wire & is controlled by the engines computer.??
FEED Pressure is VERY important to that system.. I would check the pressure going into the inj. pump..
I THINK u can adapt a fitting at the filter head.. or just replace the supply/feed/lift pump..
How about a filter screen in the outlet at the bottom of the fuel tank??

 

[jremmons]

All, thanks for the help. Both pumps are definitely running but could be weak (we have no way of testing), so I've got a JD tech on the schedule to come out when he gets a chance.

Definitely seems to be a fuel issue from the consensus here, which is kind of what I'd thought anyways. We do use two transfer tanks for all our tractors and skidsteer, but haven't had issues with any of our other equipment, but once I get the fuel down low I can maybe try draining out what is left and cleaning it well.

I do believe the pump is computer controlled and we have had several electrical issues with it due to previous use (I work for a State agency and this tractor has had many, sometimes poor, operators).

Fuel is definitely getting the to the filter, but I'm not sure if it is the necessary amount to keep full power under load.

Thanks again.

 

[MHarryE]

Tractor is Tier 1. No special engine electronics. Suspect something happened to the injection pump as you have checked/replaced the obvious - fuel filter and checked fuel line for restriction. Any chance somebody dropped something in the tank that is partially plugging the outlet? Have had some really strange fuel line blockage issues on engines in that vintage.

 

[searcyfarms]

im guessing obstruction in tank/lines/filter - smells just like a gel/slime/algae issue to me - take the fuel line off from the tank to the lift pump and observe the flow of fuel stream - turn your regulator on your air compressor down to 15lbs - burp air into that line from the air compressor - i use my rubber coated air nozzle to blow back into the line - that will blow the slime/obstruction away from the bottom of the tank and anything in the line that might be slowing the fuel down. See if you notice an increase in fuel flow, its usually pretty obvious when there is a restriction and its removed. - something to do in the mean time before the tech comes out

 

[Eagleview]

Just try loosening the fuel cap and see what happens . Sometimes the tank vent or cap vent gets blocked and a vacuum forms in the tank which restricts flow .