I'm really stumped by this problem. My 2006 JD 410G has a loss of power. It comes and goes such that if I start out simply moving the machine in forward, in 2nd gear, I see a 2200 RPM engine speed, about normal, but in seconds that can drop to 810 RPM or so, even with the accelerator full on. If I come to a hill, it barely will climb it in 1st gear. Holding the accelerator full on, it can build up to 1800 RPM, then down again. Needless to say, I can't do any work with it in this condition. It appears like there is a lack of fuel, or air in the fuel lines. To attack the problem, I have, not necessarily in this order: Replaced the fuel filter, replaced the transfer pump, taken the injection pump to a shop where on a test stand it was perfectly ok, replaced all the rubber seals on the fuel line connections, checked the check valve on the output line of the injection pump, and pressurized the fuel tank to 10 PSI for 48 hours, looking for any sign of a fuel leak - none found. I can say before any of this intermittent power issue cropped up, that even days after using the machine, when I opened the fuel tank's cap, there would be a vacuum in the tank. Now, I never see any sign of negative pressure in the tank, which leads me to still believe I have an air leak somewhere. Before I part with a thousand dollars for a John Deere field service call, would anyone have any idea what I might check next? -Thanks
Years ago my JD410 was doing almost the same thing to the point it would actually shut off.. Long story short, it ended up, My machine had what looked like long hairs in the fuel tank that were settling to the bottom and clogging the outgoing fuel.. We syphoned the fuel as a last resort, that's when we found the problem.. It was algae from what I learned later.. Good luck..
Well, first I used a bright light, looked into the filler opening, and it was pristine in there. Next, I disconnected the fuel supply hose from the tank's output fitting, and ran a clear plastic tube back to a diesel fuel can. I then pressurized the 410's fuel tank with compressed air input to the return fitting. Copious amounts of fuel poured from the plastic hose until I filled the 5 gallon can. I think I can eliminate the fuel tank as the culprit. While I had the plastic hose handy, I connected it to the metal fuel line which feeds the injection pump's inlet port. Again pressurized the fuel tank, and fuel ran out the hose, not as much as from the tank directly, but certainly enough to run the engine. At this point, I still suspect the injection pump itself, in spite of it passing a whirl on a test stand, but basically I'm out of ideas...
Do you have a screen on the fuel pickup inside the tank? Clean that and inspect for signs of collapsing. Or, tee into the supply line to the injection pump and run a hose to the cab with a pressure/vacuum gauge, that will tell you what's going on with the fuel pressure as it's losing power. Also, check the fuel return from the injection pump back to tank. Only after those tests can you blame the fuel injection pump.
Thanks for responding. The shop that tested the injection pump also told me to T into the supply line where he said the pressure should be between 4 and 7 PSI. I asked how I would do that, if there was a kit, or whatever, and he said to just go to an auto supply store, but I don't think these 17 mm fittings are a "standard" that an auto supply would have on hand. Would you have a suggestion as to how specifically to T into the steel tube supplying the injection pump? I also would like to insert a small section of plastic tube at the same location to see if air bubbles are going by.
You can just cut the steel line and tee in with rubber and hose clamps. A better way is to get a tee fitting that goes into the inlet of the injection pump, and has a flare fitting and cap to hook up a test hose to. (discounthydraulichose dotcom or other online seller) Then you can hook the existing supply line to the same place, maybe tweak it just a bit to fit. put the clear hose in the return back to the tank, if there's not air there, then there's not air getting sucked in, or run the hose into a can/jar of fuel so you can observe for bubbles.
Would you know if I have to lower the entire fuel tank to remove that pickup? The pickup is way under the top cab step, and the device must be quite deep in the tank. Although I haven't yet tried to remove the pickup assembly, it really looks like I'll have to lower, or tilt the tank to get it out of there...
No, I don't know what it takes to get at the pickup. I'd go to JDparts.com and see what is inside the tank so you're not wasting your time. On my JD there's a large hex fitting (1 1/2"?) that unscrews and the whole thing lifts out, mine's older than a 2006 by a ways...
Ah-ha - I didn't know I could see diagrams of the machine online, so thanks. The tank diagram shows that the inlet tube bends shortly after it enters the tank, so I should be able to remove it. Rather than having a screw-in fitting, mine has 6 screws holding the sensor, feed tube, and return tube as one assembly. I think the problem is in the fuel tank as many have suggested. If I blow air into the feed tube, the problem seems to go away for about 15 minutes, but returns slowly all the way to near-zero power. So, next trip to site, and I'll replace the strainer.
Well, I had to drop the tank a bit to get the feed/return tube assembly out, and discovered the strainer completely rusted. I guessed that it must have been sitting in water which would be in the bottom of the tank due to the density of water vs. diesel fuel, so I figured the tank needed to be drained to expel the water. After doing that, no water came out, but a bit of rust did from the filter. Maybe at some time in the past life of this backhoe, there was water in the tank. Anyway with a new filter installed, the machine has regained its full power. Thanks to all who responded - your suggestions were spot-on.
Thanks for the "follow up"..