Sudden Fuel Tank issue, can't refill without trouble

jross20

New member
I believe this problem started last night and it's become significantly worse today. I just can't fill the tank anymore. I noticed this while doing a lot of driving for a new years trip.

No matter what I do, when I start to put gas in it instantly triggers the auto stop on the pump. Even at a half tank, I just fact keep gently starting it again and manually watching the gauge. Of course I don't want to overfill it, so I'm not really going any higher than 3/4 of a tank. But this drastically cuts the range down.

I'm thinking now that maybe she's never actually filled up all the way since I've had her. I've noticed that the fuel economy seems to vary wildly, but now I'm curious that maybe it's due to the tank not filling up every time.

- No codes.

- 2000 SR5 4x4 auto

Any ideas? I did some searching, but a lot of the threads are pretty old and most of them didn't even have a solution.
 
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The fuel tank is not venting. Could be the tank vent, vent valve, evap canister....
Any codes? Probably need to drop the tank and check valves and hoses.
 
Mebbe bad rollover valve w/gasket on top of gas tank?

Someone did a thread about R/R but he had a PO440 + PO446 code too-
 
The fuel tank is not venting. Could be the tank vent, vent valve, evap canister....
Any codes? Probably need to drop the tank and check valves and hoses.

Shit, well that sounds like a job for my mechanic then. Damn.
Is any of that cheap enough to go ahead and order before hand?

Any idea what the part numbers for those 3 items are?

Also, no codes but I'll try to pull again later.

Mebbe bad rollover valve w/gasket on top of gas tank?

Someone did a thread about R/R but he had a PO440 + PO446 code too-

No codes yet, I'll try to pull again but so far the only symptom is the filling problem.

Is that value cheap enough to go ahead and swap if they do drop the tank?

If they have to drop it, I feel like I might as well swap anything cheap while we are there... Haha.
 
Can't really say what you need part wise without a proper diagnosis but shouldn't be too expensive. The vent valve is probably around $50. That's a guess!
 
Can't really say what you need part wise without a proper diagnosis but shouldn't be too expensive. The vent valve is probably around $50. That's a guess!

Shoot, yeah that's not much for the peace of mind even if that part isn't broken yet.
 
They started venting the tank through the EVAP system in 99 I think. (onboard vapor recovery) Could be the check valve in the top of the tank, but it might be the canister itself or the vent control solenoid valve. On some cars (Hyundai come to mind) the canister breaks down and fills the system with charcoal pellets causing the symptoms you describe.
 
If you drop the tank change the fuel pump and the filter screen around it while you are in there.
 
Usually when unable to fill the tank, it is either the solenoid (a scan tool with the right EVAP sub setting can tell you if it is venting or not) and most of the time some EVAP code is thrown for a leak, or the charcoal canister is plugged(no code). My gut would say it is the latter even though I have never touched the EVAP system on this 4Runner except to change out vacuum hoses.

In my experience, when vent valves fail, you will get real strong heavy fumes throw back at you or gas is even spit back at you. Doesn’t sound like the case here.

Try filling next time with the gas pump nozzle halfway out the filler tube and see if you can fill up with less resistance.
 
Usually when unable to fill the tank, it is either the solenoid (a scan tool with the right EVAP sub setting can tell you if it is venting or not) and most of the time some EVAP code is thrown for a leak, or the charcoal canister is plugged(no code). My gut would say it is the latter even though I have never touched the EVAP system on this 4Runner except to change out vacuum hoses.

In my experience, when vent valves fail, you will get real strong heavy fumes throw back at you or gas is even spit back at you. Doesn’t sound like the case here.

Try filling next time with the gas pump nozzle halfway out the filler tube and see if you can fill up with less resistance.

Interesting.

I've not noticed any fumes but I'll check for them when I fill up tonight. Also, checked for codes again and still don't see anything.

Lastly, do you have the part number for the charcoal canister?

I've basically decided that if we're going to have to drop the tank I might as well swap out anything that can go bad. Unless it's ultra expensive
 
I've experienced something like this before on a different truck, but if I rotate the nozzle a little, it helps a lot.

Not ideal, but might be worth a try.
 
Yup, my old Wagoneer had this issue that I never bothered to resolve before I finally got rid of it. My solution was to simply fill with the nozzle upside down. It tricks the pump into not shutting off at all. The downside is you have to actually pay attention to how much you're pumping or you risk overflowing.

I'm sure there was a break in the early 80s evap system somewhere down the line that was really causing the issue, but what the hell. The thing wasn't very environmentally friendly or fuel efficient when it was new from the factory anyways. Also wasn't exactly known for its reliability.
 
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I've experienced something like this before on a different truck, but if I rotate the nozzle a little, it helps a lot.

Not ideal, but might be worth a try.

I will try this a bit later today when I get gas. Someone else said to pull it out slightly to help the air escape.

The number is 77740-35392 though you could probably find one in a junkyard for much less.

Thanks I'll look it up. Is it worth it to get a used one?

Yup, my old Wagoneer had this issue that I never bothered to resolve before I finally got rid of it. My solution was to simply fill with the nozzle upside down. It tricks the pump into not shutting off at all. The downside is you have to actually pay attention to how much you're pumping or you risk overflowing.

I'm sure there was a break in the early 80s evap system somewhere down the line that was really causing the issue, but what the hell. The thing wasn't very environmentally friendly or fuel efficient when it was new from the factory anyways. Also wasn't exactly known for its reliability.

:pout:
 
Personally I would. Usually they can be had for $30 or less in Virginia and South Carolina. As long as the seal is good, you should be fine. You could also snap up the EVAP solenoid as well for cheap.

It isn’t as if the filling up problem is killing ya somewhere in the short run, just more of a PITA.
 
Personally I would. Usually they can be had for $30 or less in Virginia and South Carolina. As long as the seal is good, you should be fine. You could also snap up the EVAP solenoid as well for cheap.

It isn’t as if the filling up problem is killing ya somewhere in the short run, just more of a PITA.

Well I don't like not feeling up perfectly each time. Removed the ability to calculate fuel economy and also makes the trip counter unreliable for "range" since i may not always feel it to the same level.

I went ahead and just ordered pretty much all of the components for the tank. After my mechanic said we'd need to drop it (after he inspected things for a while) I just said screw it, might as well refresh it.

Ordered a oem fuel pump and the newer fuel sender since mine is the older crappy one. Gaskets and all that jazz. The added peace of mind will be good.

I'll follow up one it's all in.
 
I’ve noticed mine having this only taking 3/4 of a tank issue the last 2 times I filled up, but only at this particular station (3 different pumps- I went to 2 tonight to see if that helped). I can smell gas and hear gurgling when it gets to 3/4 then it keeps shutting off. I tried pulling it out some, didn’t work. Going slower did work for a gallon or so, but then the pump stopped. I have no CEL or anything.

It’s a minor inconvenience, this is my fun/moving something large car. If it doesn’t have any affects on performance or reliability, I’ll leave it.
 
Well I don't like not feeling up perfectly each time. Removed the ability to calculate fuel economy and also makes the trip counter unreliable for "range" since i may not always feel it to the same level.

I went ahead and just ordered pretty much all of the components for the tank. After my mechanic said we'd need to drop it (after he inspected things for a while) I just said screw it, might as well refresh it.

Ordered a oem fuel pump and the newer fuel sender since mine is the older crappy one. Gaskets and all that jazz. The added peace of mind will be good.

I'll follow up one it's all in.

so did you fix it ?
 

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