HOW TO: fix the KJ fuel burp plague!

Discussion in 'How To' started by ol-flattop, Nov 28, 2014.

  1. profdlp

    profdlp Grouchy Old Cuss

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    It's supposed to get to almost 50F here by midweek. If I get ambitious I might try this then. I sure would like to have this solved. Depends on some other calls I'm expecting, though.
     
  2. nullptr

    nullptr Full Access Member

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    Just did it on my '05. A couple of things came up while doing it that I think others may like to know.

    • WD40 sprayed into the hose makes sliding both the valve, and the hose back onto the gas tank, much easier
    • Do not over-tighten the clamp over the valve, just snug works. You'll want to make sure the flapper still moves freely.

    Now to clean up and head out to a gas station and dinner. :gr_grin:

    Thanks for the writeup, ol-flattop!

    Edit: Works perfectly! The only downside was not being able to pump at full speed, as that would cause it to shut off. Makes sense, since there is now a slight restriction in the line. However, it shut off perfectly without doing any of the burping. This fixes the problem and is stupid simple, short of the half hour I spent trying to get that stupid filler hose off, to do. If you have the fuel burp issue, order the part and the rivet kit, it's worth taking the time to do.
     
    Last edited: Jan 25, 2015
  3. spta97

    spta97 Full Access Member

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    First, thank you for this thread. Now a couple comments:

    1) Has everyone who installed this had an issue with not being able to pump at full speed? If so, is it possible to take the existing valve out or replace the hose assembly with a new OEM hose?

    2) Any concerns with the longevity of the GM part?
     
  4. nullptr

    nullptr Full Access Member

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    Yes, I can pump at between 1/2 to 3/4 speed. Full speed causes the shutoff to trigger. I suspect this is because the new valve is causing a restriction in the hose. A different, larger, valve would probably not have this problem but would require cutting the hose.

    The part itself isn't much more than a plastic cylinder with a metal rod through part of it, and a plastic flapper attached to the rod. It's not in an area it's likely to get banged on, so it should last quite a while. I believe the part is actually GMs answer to a similar issue on their vehicles, and shouldn't suffer from the same 'swollen rubber gasket' problem as it doesn't have one.
     
  5. ol-flattop

    ol-flattop Full Access Member

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    I've had no issues with auto-shutoff, even on pumps with huge flow rates. I'm fact, my only issue has been that sometimes, when the flow rate is really high, there has occasionally been a small burp as the tank reaches capacity. It's rare, and unless I notice the meter going extraordinarily quickly, I just start the pump and let it go all the way to auto-shutoff, which only occurs when the tank is full.

    Null covered the longevity concerns. I have no worries, it's too simple to fail in ordinary circumstances.
     
  6. bovine

    bovine New Member

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    I just did this fix to my 2006 Liberty and it definitely fixed the overflow problem. I didn't notice any problems refueling at full speed at the Costco fuel pumps either.

    I too had difficulty removing the hose from the bottom of the filler spout. Maybe it's possible Jeep might actually have used some type of adhesive or sealant around that connection, in addition to the hose clamp? I ended up inserting a flat screwdriver around the inside of the hose to help break loose its connection to the filler spout prior to pulling it off.

    I initially tried to simplify the install by fitting the GM flapper valve in the top end of the Jeep filler hose, but the inner diameter of the hose there is too narrow there. Removing the hose entirely and inserting the flapper at the lower end of the hose as the OP described was indeed the best option.

    To help ease the re-install of the hose on the fittings, I sparingly applied a little bit of liquid dish soap.

    Here's a video of the overflow problem before the fix: https://www.youtube.com/watch?v=E57ThoqKTzw After the fix, it stops as expected without any problem.
     

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  7. nohitter64

    nohitter64 Full Access Member

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    Gents, I have the parts and am ready to go. One question for clarification. In Step 11 of the OP, what exactly are you marking?
     
  8. ol-flattop

    ol-flattop Full Access Member

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    Sorry about the delay, I’ve been on a road trip and just haven’t had any spare time. Now that I’ve got a chance though, I’m glad to help!

    I marked the top of the filler hose, as it sits when connected to the tank. You have to twist the hose a bit to access the open end and insert the flapper valve, so it can be a bit tough to tell where the true top is. In case you’re just not seeing the mark in the picture, try playing with your brightness and contrast. It’s a little tough to see, I admit.

    The purpose of this is to give a reference for properly orienting the flapper valve in the tube. If you get it a few degrees off, it won’t make any difference, but if you get it too far to either side, gravity won’t bias the valve toward closing, and the backrush of fuel will likely not close the valve, so the belching problem won’t go away.

    I hope this helps! I’ll be happy to answer any other questions. Good luck with the fix!
     
  9. nohitter64

    nohitter64 Full Access Member

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    Thanks flattop. I'll let you know how it works out.

    Sent from my SM-G900V using Tapatalk
     
  10. ol-flattop

    ol-flattop Full Access Member

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    Thanks for your input! I'm thrilled that my work is helping people out.:High 5:

    In regards to the dish soap, while it's a good idea for a lubricant, and I did see the word 'sparingly', I wouldn't recommend others do this. When I consider that dish soap is used to clean oil off of waterfowl, it makes it seem like a bad idea to put it into lasting contact with any petroleum product I don't want to ruin. In this case, I'm sure that the regular flow of gasoline through the valve will help prevent the excess from causing issues, but as for the small amount that's actually stuck between the valve housing and the hose...well, I doubt it will be a problem, but I still wouldn't recommend it. WD-40 is a better option, especially since it loses its lubricity as its solvents evaporate, leaving a good, tight interference fit between valve and hose, with no lingering lubricant in between. Frankly, I wish I'd thought of it myself. :emotions122: There's another tidbit that I'll eventually need to add to the OP.

    By the way, since working out this fix, I've relocated to a city where ethanol-free gasoline is available at just about every fuel station, and that's what I've been feeding my jeep. Contrast that to my last home, where an ethanol-free gas pump couldn't be found within a 2-hour radius! I'm seriously tempted to order another hose from mopar, switch it out for my current one (which incorporates the flapper valve), and see what happens! It might help to indicate whether this issue is from chronic or acute ethanol exposure. Currently, the few accounts I've seen are divided on this point, so I'm looking forward to putting it to the test. It's pretty far down on the to-do list, but I'll be sure to post results if I ever get to it.
     
  11. profdlp

    profdlp Grouchy Old Cuss

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    Just to add to the speculation about the ethanol, back in Ohio I was able to find some ethanol-free gas here and there. Not always, but sometimes. Since relocating here to the D.C. suburbs I can't find it anywhere. The burp issue seemed to have gotten much worse here.

    About a six weeks ago my engine seemed to be acting a little weird and on a whim I started adding Marvel Mystery Oil with every fill-up. (4oz per every 10 gallons, as recommended.) Oddly enough, I have not had one single instance of the fuel burp problem for about a month now. I have been driving a lot this summer and am filling up about every 5-6 days. I didn't turn to the Marvel Mystery Oil to solve the fuel burp problem, but it does seem to have the added side benefit of alleviating it. If it is indeed the reason for the improvement I'm guessing that it counteracts the effect of the ethanol on the (supposedly) one-way valve in the hose.

    I wouldn't consider this a real "fix" - I think the method you describe here is the way to ultimately solve this - but for anyone who might care to experiment, it might prove interesting to see if the MMO helps them too. It took two or three fill-ups for the burping to stop, but it hasn't reoccurred for the last five or six fill-ups in a row - something that has never happened before. This leads me to believe that the quality and/or composition of the gasoline is a big factor in this, and not solely a design flaw in the valve.

    (And yes, I agree, a design which doesn't take into account the @#$% gas the government is forcing on us is definitely flawed, just that it's not purely a bad valve design problem. There is a distinction between a valve which never works right and one which doesn't work due to outside factors, albeit ones which should have been foreseeable.)
     
  12. Tanji

    Tanji Member

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    So what does one do if they have both the fuel burp issue as well as the nozzle clicking for a while right when you start to fill the tank up?
     
  13. ltd02

    ltd02 Comfortably numb KJ Supporting Member

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    Not much of a cure from me. When I got my 05 a couple years ago it would always do the quick shut off several times when I first started pumping. I figured out the position of the nozzle that would avoid this. I also usually guesstimate how much it will take and slow it down at the end. I usually only go to maybe three different stations and the one solved the overflow at the end since their pump is always slow... :emotions34:
     
  14. Tog

    Tog Full Access Member

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    I had both issues had to drop the tank blew out all lines from the tank to the charcoal filter with compressed air . Problem solved

    Sent from my SM-G960F using Tapatalk
     
  15. Jeremy-WI

    Jeremy-WI Full Access Member

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    Sounds like the valve isn't totally stuck yet as mine was stuck open and I had fuel burp, but if the valve is just slow to open and close you could have those issues
     
  16. nohitter64

    nohitter64 Full Access Member

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    Tog, Any more details on how to do this? I plan on dropping the tank soon to swap out the fuel pump.