# JD 6420 fuel problems



## ANewman (Sep 20, 2012)

My buddy, that I work for some, has a 04/05 JD6420. For the last 2-3 years he has had constant fuel system problems. The injector pump was replaced about two yrs ago. Last year new injectors. (I think one was replaced. He thinks all four were.) A couple months ago it started acting up again. It would start run 3-5 seconds then shut off. Would not start back until the fuel system was bled. It might start the next few times, but after a day or two it'll start then die. Yesterday, I tried starting it. Died after a few sec. Tried bleeding the system three times, but it never hit a lick. Deere service came out and finally got it started but it would not run right. He says it need new inj. Pump and injectors. He blames it on bad/dirty fuel and asks where we buy fuel. This is the second go 'round in two years with basically the same problem.
He (my buddy) only has about 12 other various diesel engines that run fuel from the same place with relatively few problems. He only buys road fuel and only from one station. During our busy time his fuel bill is about $8-10k/mo.
He really likes the tractor but is seriously contemplating getting rid of it and replacing it with a Case. Does anyone else with the 6X20 series have constant fuel problems?


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## mlappin (Jun 25, 2009)

Sounds like a lemon to me, we buy premium B5 diesel from the co-op and personally feel even the newer pumps that are rated for low sulfur fuel can stand extra lubrication. On the Dodge Cummins forum they claim even adding a quart of two stroke oil to every fill up will drastically increase pump and injector life.


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## somedevildawg (Jun 20, 2011)

I agree he may be experiencing some problems with o ring failure by using pump fuel. I had a 6715 that had similar problems, replaced lines, filters, o rings, put a stupid little check valve (deere fix) never got to the injector pump, traded it.....it ran great once it was cranked and running for the day, but if yu let her sit for a couple of days you would sometimes play hell cranking her up. Green tractor talk is a good forum for Deere related problems, good many Deere mechanics lurking on there.....good luck, I have a 6420 and love it, until the day it quits cranking......


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## wildcat (Oct 20, 2012)

Had the same problem with my 6420 some years ago. Replaced all the rubber lines and haven't had the problem again. Apparently the rubber deteriorates over time and actually collapsed on the inside. I also add a quart of chainsaw oil every other fill up. Was told by a mechanic that todays fuel doesn't contain enough lubricant. Good luck!


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## somedevildawg (Jun 20, 2011)

wildcat said:


> Had the same problem with my 6420 some years ago. Replaced all the rubber lines and haven't had the problem again. Apparently the rubber deteriorates over time and actually collapsed on the inside. I also add a quart of chainsaw oil every other fill up. Was told by a mechanic that todays fuel doesn't contain enough lubricant. Good luck!


By saying chainsaw oil....you're speaking of 2-cycle oil not bar oil right.....just to make sure others know.....


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## wildcat (Oct 20, 2012)

Yes, 2 cycle


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## endrow (Dec 15, 2011)

check for algae in the fuel


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## FCF (Apr 23, 2010)

endrow said:


> check for algae in the fuel


or some other problem in the tractor tank that could be stopping flow at the fuel pick-up.


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## ANewman (Sep 20, 2012)

wildcat said:


> Had the same problem with my 6420 some years ago. Replaced all the rubber lines and haven't had the problem again. Apparently the rubber deteriorates over time and actually collapsed on the inside. I also add a quart of chainsaw oil every other fill up. Was told by a mechanic that todays fuel doesn't contain enough lubricant. Good luck!


They replaced the rubber fuel lines when they replaced the original injector pump and also added an in-line check valve.



FCF said:


> or some other problem in the tractor tank that could be stopping flow at the fuel pick-up.


On the first go 'round, two yrs ago, the fuel tank was completely removed and inspected/"cleaned"


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## wildcat (Oct 20, 2012)

There is also a electric pump mounted on the frame, but I'm sure that has been changed as well?


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## ThreeTieMan (Apr 9, 2011)

What injector pump does it have? The DE-10 or a HPCR system. The DE-10 has only two wires connected to it with no throttle linkage. Other then that it looks like any old rotary injection pump. The two wires carry signals from the engine control unit to the pump. This includes fuel on/off, throttle, timing advance and maybe some other things. Sometimes the two wires have bad connections and the tractor will act like your's does. I had a customers 6420 that was hard to start, would start and and then die, and once it was running it would run poor and other times it would start up and run fine. Turned out that the wires were almost broke off at the connection on the pump. You could move the wires and then the tractor start right up and run great. Deere has a service bulletin about the wires and recommends replacing the wires.

HPCR looks completely different and has wiring to sensors. solenoids, injectors, valves. Plus, wiring, valves and/or the pump or injectors could be bad.

The other thing is fuel quality. Low sulfur diesel does not help any fuel system with lubrication. It is a good idea to use a fuel conditioner in both the winter and the summer. John Deere sells both a winter and a summer conditioner. Both help with lubrication and water displacement. The winter also helps prevent gelling at cold temps. Stanadyne also sells a good additive. One of the only reasons we have low sulfur diesel is because of the eco-freaks and extra refinement required makes diesel cost more the gas. I would not recommend using random oils like 2-stroke or ATF, etc.

Make sure your fuel is clean when you buy it and that it stays clean. You may have a storage/transfer problem. No diesel fuel system likes rust, dirt, or water. But newer Systems don't like it even more then the old ones. Just a little bit of contamination making it past the filters will wipe out a set of injectors, $2400 just in parts for a four cylinder HPCR. The first filter on a HPCR engine is a 10 micron and the second is a 2 micron. 1 Micron = 0.000039 of a inch.

Be sure and check the water separator (on the bottom of the first filter) and drain if it there is water in it. If the water gets too high it can go through the filters.


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## mikegxp3 (May 5, 2014)

I just read through these posts and would like to suggest Xp3 to anyone experiencing fuel system problems. Almost everyone mentioned something in a post that could potentially be a problem for a fuel system... insufficient lubrication because of lower sulfur amounts in diesel, water in fuel, bio-fuel providing less lubrication, algae in the fuel tank, and the list goes on.

Some people on this forum have mentioned using Stanadyne. If you are using that product or any other fuel additive, you have to check out Xp3. Watch this video linked here where I demonstrate the key differences between Xp3 and other products on the market that are oil based. https://www.youtube.com/watch?v=Y-7yvD7q4pA.

I have several customers that run farms and farm equipment who are really liking the results of this product.


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