Hello, I have a Deere 710G that has a rough idle, and bogs under load. The problem comes and goes, sometimes the machine will run an hour perfectly, and then the next time it starts it will have trouble right away. I have not been having rough start problems though. Some more background on the machine, this was an auction buy (new to me) meter says 1100~ hrs, which I believe is accurate. It was run as a hammer hoe in California. I saw the old fuel filter on the machine said 1050 HRS and a date of 2020, so obviously it has had very little use the last few years... The first thing I did was check the water separator, didn't see anything. Since the fuel was old I pumped it out from the filler neck, pumping from the bottom of the tank. Replaced with new fuel, and new fuel filters. No change. I don't think there is a hole in the pickup tube because you will experience the problem whether it is full or lower. I took EGT readings with an IR temp gun, 2 cylinders seemed significantly colder. Did a cutout test and noticed no change. I decided to pull the injectors and have them pop tested. 3 readings of about 210 bar and the other 3 were about 245-252 bar. Replaced all injectors with new Stanadynes, and new seals between the injector lines of course. No change in performance, I am confused now... Machine is throwing no codes. What should I look for next? When I replaced the injectors and went to prime the machine by pressing the black rubber piece on top of the fuel filter head, I noticed it was leaking, but it stopped when I was no longer pressing it. Haven't replaced that yet. I have been thinking of cleaning the fuel tank and blowing with compressed air the line from the lift pump to the tank. Not sure if this is a fuel starvation / supply issue or what. Bad injection pump? All input would be appreciated. Thanks.
There is a strainer in the fuel tank that is removable with the pickup, that is probably nylon screen and will collapse if it gets plugged up. The hose is shop fabricated so probably rubber, check the bends at the end for cracks, cut off any cracked parts and reattach. I didn't bother to check what injection pump it has, and wouldn't know the issues there anyway.
Thank you. I plan to investigate the pickup tube tomorrow.
Does the primary fuel filter have a glass bowl on the bottom? Make sure the seal is there between the bowl and the filter. many people seem to miss that when changing filters and it will allow air intrusion into the fuel system. Definitely check the fuel strainer like Delmer said. A fuel pressure test could tell you if that is an issue. Did you check fuel pressure? Measure it on the final fuel filter's filter head. What is it cranking vs running? Idle vs Full throttle? You said you did a cutout test. Do you have diagnostic software?
No glass bowl. Will look into fuel strainer today, thank you for the exploded view. I agree with you on checking fuel pressure. I have never owned a gauge set. Is there one you recommend that works with Deere equipment or should I set any old gauge up with fittings I can find? I did a cutout test by cracking the injector lines. This machine is not common rail. I do not have diagnostic software. Thank you.
The inj pump is a DE electronic inj pump. (They’re garbage)
I just pulled the pickup tube. Here is a picture of what it looks like. Also, it’s collapsed like Delmer said. Looks to be very occluded with red dirt. Also, before I pulled it, I blew with compressed air backwards into the tank and the machine started running ok. So this must be the trouble?
That's not half bad, but you see where it flattened and lost most of the surface area. I think that gunk will dissolve in flammable brake cleaner. You could try to wind a spring inside to keep it open in the future, it should work fine as long as it stays clean though. I've some times used a larger diameter pickup to a large diameter filter head with a cheap oil filter (like ph2 or ph8a) and then onto the standard fuel filter. If you plug a ph8a with diesel fuel, just throw it on a bonfire and put a new one on for few bucks. Another option would be removing and cleaning the tank, or pressure washing it in place.
I already removed the tank. I tried cleaning the screen, and yes most of that dissolved. I think I will get a new screen. The tank itself doesn’t look too dirty or rusty, but what is the best way to go about cleaning one?
That's not bad either. Since you already have it off, a couple gallons of E85 and let it slosh around strapped in the back of a pickup for a week, sometimes add some nuts if it's bad enough. Or pressure wash. Another method is to strap it to a tractor tire, or small concrete mixer, and tumble nuts or gravel, but yours looks like just a light coat on the bottom, nothing on the sides and top that would need that treatment.
I ended up pressure washing through the pickup tube hole and the fill neck. Got the bottom as well to loosen all the rust flakes and rinsed till it came out clear and used a little simple green too. I just tilted it and drained everything from the drain plug. Anything left should be gone in 24 hours since the high was 108 today.
Just curious was that fuel screen the problem we have a 710g runs perfectly fine until about mid day and wants to bog down and shutoff.
Look at the pictures. I removed the pickup tube, and there is this nylon strainer bag looking thing on the end of it. It was pinched and collapsed because it was so dirty it must have created a suction.