[indyguy9791]

Originally Posted by 4wheel4real
I have been having a weird issue with my gas tank (I think). Now it does have a dent in it but it has been having this issue before the dent was there. When ever I go to fill up at the pump the pump handle always pops as if its full and I know its not..it will do this on a half tank of gas..it's really starting to get annoying because I can't tell when I'm actually getting full or not. Like on Sunday I spilled gas out of it because I have no idea when it's getting full, I have to squeeze the handle at a certain point to get it to flow right. If I pull the handle all the way up and push the medal clip down to hold it there it just stops pumping.. Has anyone else had issues like this? How does the pump know when I'm full?

RE: filling fuel tank problem
I also just started having the same issues while "TRYING" to fill my tank. It's a '90 wrangler-4.2 & I never had this problem until the past 2 months.
I've pulled the nozzle up/down, side to side, very slow squeeze of the trigger and after about 10 mins. of it just acting like it's full (gas pouring out of filler pipe) I normally give up with just 5-10 gallons. (if I'm lucky). I looked for the vent tube/breather, what I saw with out dropping the tank was a hose that ran down & "T'ed" into a block that was mounted to the rear axle..?? Is this the fuel tank vent? OR is there somewhere else I need to look for this vent?

Thanks for ANY other help!!

[rustywrangler]

Unfortunatly, aside from doing a TJ filler tub conversion, this is kinda normal for the YJ. Both of mine have done it.

[mxracer513]

yeah my yj does it alot of the time...it sucks lol

[dell2028]

Mine does this as well. If I pull the nozzle out of the filler tube about an inch or two from all they way in and it helps some.

[Burnerman]

what I saw with out dropping the tank was a hose that ran down & "T'ed" into a block that was mounted to the rear axle..??

The rear axle vent tube runs up alongside the fuel filler on mine. I have the plastic inner fender things and when I was wiring up my trailer plug I found the end of the diff breather is way up there behind the DS taillight. This should not be tee'd into the fuel filler lines. I have no trouble filling my heep. I would suggest dropping the tank and looking for the kinked or crushed smaller vent line that runs up to the metal filler neck.

[hevybluzer]

Mine does that "maybe I'm full, maybe I'm not crap all the time. The best is when, after you cajole the damn nozzle to the right position, the tank really getting to be full, and the damn thing blows a quart or so gas back at you without "tripping" the handle safety catch. Real thrilling!!!!!!Makes the ladies at the Quik-Fill soil themselves (I don't know if soiling occurs from fear...or laughing at the idiot with the gas up his arm again!!!)

[zeus87gn]

Fellas, what you are talking about is fluid dynamics. I have a knowledge of this as I am in the business of measuring petroleum products. I also helped design the metering valve on certain types of gas pumps back when I was shortly out of technical school.

The gas tank has a filler tube and a breather tube. The breather tube is smaller than the filler tube as it only has to vent fumes. BUT, the passageway at the filler neck (where you stick the gas nozzle) for the vent tube is quite a bit smaller than the filler tube hole where you stick the nozzle in.

The filler nozzle works on back pressure. When the balance of vent and filler tube equals the right pressure within the gas tank, the nozzle senses it and cuts off. The problem is that we are dealing with old technology on our gas tanks. The nozzles today are calibrated to work with newer vent systems. Our old antiquated venting wasn't designed well in the first place.

If you want to stop the hassle, and have it work better without spillage of the "liquid gold", run the pump on a slow setting. It lets the gas flow more evenly, the pressure equalizes better, and you may even get a drop or two for free as certain pumps don't meter as well at slow speeds.

HTH

[jbowers]

Originally Posted by zeus87gn

If you want to stop the hassle, and have it work better without spillage of the "liquid gold", run the pump on a slow setting.

Ding ding. Had the same problem till I slowed her down.

[SWAMPED]

i have that problem too if i try to pump fast. when pumpin fast it stops at 12-13 gallons, but it holds 18 so u just gotta pump slower.

[Big-n-Broke-YJ]

all this talk about pumping slower and pumping faster, sticking it in a little and tot he left, pulling it out except for a couple inches, liquid gold getting all over yourself, excessive spillage... what were we talking about again?

[ImSuck]

my tj does this, it will stop filling after like 10 gallons then i have to click it all the way to 21 gallons which is where it should be. i will sit there for literally 20 min pumping gas, cars will come and go and ill be standing there pumping gas still. i freakin hate that so much.

[indyguy9791]

The filler nozzle works on back pressure. When the balance of vent and filler tube equals the right pressure within the gas tank, the nozzle senses it and cuts off. The problem is that we are dealing with old technology on our gas tanks. The nozzles today are calibrated to work with newer vent systems. Our old antiquated venting wasn't designed well in the first place.

If you want to stop the hassle, and have it work better without spillage of the "liquid gold", run the pump on a slow setting. It lets the gas flow more evenly, the pressure equalizes better, and you may even get a drop or two for free as certain pumps don't meter as well at slow speeds.

HTH
[/QUOTE]
RE: Zeus87gn... I can understand what you're saying about old & new style systems however, I've not had this problem before until just the past few months! Believe me I have tried different angles, depths & nozzle trigger speeds. I've spent up to 10+ minutes doing this and only end up with 5 gal.
It makes sense what you're saying but I think it's more likely to be a vent issue (hose,etc.) on the Jeep not the pump/nozzle since I've owned it a year now & it's just now doing it..
Thanks for the info...

[jeepross]

Pump gas at a slower rate, will never spill over, or cut out.

[indyguy9791]

Originally Posted by jeepross

Pump gas at a slower rate, will never spill over, or cut out.

I was just wondering how many people are actually READING Before they reply??!! I keep getting "slow down on the pump", etc. I HAVE STATED THAT I HAVE DONE EVERYTHING AT THE PUMP!!! I will check out my hoses/vent on the filler/tank like the others who have READ the thread & then gave me advice.....


But Thanks for your "TIP" anyway......

[zeus87gn]

Originally Posted by indyguy9791

Zeus87gn... I can understand what you're saying about old & new style systems however, I've not had this problem before until just the past few months! Believe me I have tried different angles, depths & nozzle trigger speeds. I've spent up to 10+ minutes doing this and only end up with 5 gal.
It makes sense what you're saying but I think it's more likely to be a vent issue (hose,etc.) on the Jeep not the pump/nozzle since I've owned it a year now & it's just now doing it..
Thanks for the info...

Ok, if this is something that has just started you may need to check you filler and vent hoses. I found my Jeep was leaking liquid gold when I would park at strange angles. I ended up finding out that my vent and filler hoses were dry rotted beyond belief! I changed them with brand new fcty replacements and haven't had a problem since. Filling the tak was never really a problem for me as I always run the pump slow since I started in design engineering.

If they are old looking and fraying, they could be fraying on the inside, thus causing strange back pressure. You can get into you rear fender and remove the hose clamp and check it out. Have a new clamp handy as you will probably mess up the old one.

HTH