Can't pump gas

[MIC_uhh]

2001 4runner sr5 4wd

Whenever I pump gas the pump will shut off prematurely. I have to do it very slowly and it takes a good 5-10 minutes to fill a whole tank (start to finish, and empty or full). Doesn't matter what gas station I'm at or other conditions.

It seems that there is some pressure building up or the gas is not flowing fast enough into the tank and is getting backed up.

From what I have read this could be a filler neck tube, vent valve, or charcoal cannister (I have already checked rubber lines for blocks).

I'm not exactly sure how to diagnose which of the above is the culprit, so if anyone has an idea how to go about fixing let me.

 

[kryptonitewhale]

What year is it?

 

[fourfive]

Whenever I pump gas the pump will shut off prematurely. I have to do it very slowly and it takes a good 5-10 minutes to fill a whole tank. Doesn't matter what gas station I'm at or other conditions.

It seems that there is some pressure building up or the gas is not flowing fast enough into the tank and is getting backed up.

From what I have read this could be a filler neck tube, vent valve, or charcoal cannister (I have already checked rubber lines for blocks).

I'm not exactly sure how to diagnose which of the above is the culprit, so if anyone has an idea how to go about fixing let me.

What year is your 4runner? Mine is an 02 & for me it was the overfill check valve on top of the gas tank but I'm pretty sure that part is specific to 01-02 4runners. I followed the FSM testing procedures which is how I was able to get confirmation. The gas pump shutting off was going on for about a year & I eventually got a P0440 evap code. Looking up the code in the fsm is what gave me a direction to go for testing. It was tedious but not hard & very doable. Even if you don't have a code, the fsm testing procedures will help identify if there is an issue within that system. I'll still very occasionally have the gas pump shut off on me but it's pretty rare & if it does happen, once I start pumping again everything is good.

If you scroll down to post #8 in the link you'll see the pages in the fsm I followed. P0440 Fixed!

 

[Outrider]

OP - on yours, does the fuel pump nozzle shut off prematurely the entire time that you are filling your tank, or only during the last half gallon, or gallon?

On my '99, I have to keep "topping off" the filling process during the last gallon or so, every single time I refuel. I do know that this is a known issue (but I don't recall exactly what the problem is), and I also know that it is yet another thing that I have just learned to live with, because dealing with the symptoms is easier and cheaper than solving the problem (like I did with the flakey fuel gauge for 14 years, but I eventually and recently fixed that - I think).

But if mine did this during the entire process (instead of only the last gallon or so), then I would definitely fix it.

OP - If you will update this thread to address my question (at the top of this post), and let us know what year your T4R is, then we can all better help you with this.

 

[MIC_uhh]

updated original post

Its a 2001 4runner sr5 4wd.

 

[MIC_uhh]

OP - on yours, does the fuel pump nozzle shut off prematurely the entire time that you are filling your tank, or only during the last half gallon, or gallon?

On my '99, I have to keep "topping off" the filling process during the last gallon or so, every single time I refuel. I do know that this is a known issue (but I don't recall exactly what the problem is), and I also know that it is yet another thing that I have just learned to live with, because dealing with the symptoms is easier and cheaper than solving the problem (like I did with the flakey fuel gauge for 14 years, but I eventually and recently fixed that - I think).

But if mine did this during the entire process (instead of only the last gallon or so), then I would definitely fix it.

OP - If you will update this thread to address my question (at the top of this post), and let us know what year your T4R is, then we can all better help you with this.

Happens during the whole filling process :mmph:

 

[MIC_uhh]

What year is your 4runner? Mine is an 02 & for me it was the overfill check valve on top of the gas tank but I'm pretty sure that part is specific to 01-02 4runners. I followed the FSM testing procedures which is how I was able to get confirmation. The gas pump shutting off was going on for about a year & I eventually got a P0440 evap code. Looking up the code in the fsm is what gave me a direction to go for testing. It was tedious but not hard & very doable. Even if you don't have a code, the fsm testing procedures will help identify if there is an issue within that system. I'll still very occasionally have the gas pump shut off on me but it's pretty rare & if it does happen, once I start pumping again everything is good.

If you scroll down to post #8 in the link you'll see the pages in the fsm I followed. P0440 Fixed!

2001 4runner sr5
I don't have the P0440 code, (could've been cleared by previous owner though. Bought the truck a few months ago) but I looked at the link you posted and may go ahead and check charcoal cannister and check valve if I don't find anything wrong with my filler neck.

When you had the issue did you notice any pressure or gas coming back up the fill neck? It's hard to tell but it almost seems like when I pump gas at normal speed the gas isn't able to run down fast enough causing the shutoff.

 

[phattyduck]

Any chance the pumps have recently upgraded to the California style vapor recovery pump nozzles? They are very sensitive to pressure changes during filling.

Not discounting the fact there might be an issue, but it could be how you are inserting the nozzle. You have to press it all the way in, then rotate it down to kinda 'lock' it in place. That seals the nozzle to the filler neck and gives you the best chance of a successful continuous fill up.

-Charlie

 

[MIC_uhh]

Any chance the pumps have recently upgraded to the California style vapor recovery pump nozzles? They are very sensitive to pressure changes during filling.

Not discounting the fact there might be an issue, but it could be how you are inserting the nozzle. You have to press it all the way in, then rotate it down to kinda 'lock' it in place. That seals the nozzle to the filler neck and gives you the best chance of a successful continuous fill up.

-Charlie

No I'm in Colorado and our pumps are pretty basic. But I was planning on driving to CA and am aware of their pumps so I'm worried I may not be able to get gas at all.

 

[diverscale]

the evap system might simply be clogged or there is something wrong with the charcoal canister or its system. The gas pump would sense that there is a pressure building inside the gas tank as you gas up.

Could try unplugging the hose and see if it's clogged, or see if you can fill up with it disconnected.

Could also try something like this (never tried so I don't know the results)

Fixing A Car Where The Gas Pump Keeps Shutting Off - YouTube

 

[AJPuleo23]

I've had the same issue as OP for years.

Strangely, it seems to occasionally fill up "normally" if I don't lock the gas pump on the fastest fill notch under the trigger. So I have habitually just not used the fastest fill setting to see what I'll get.

Then there's this whole OCD thing I've got where I like to have the bill stop at an even number (don't judge) so it is very possible I was the culprit for the initial issue after very likely overfilling the tank to scratch my OCD itch.

That said, I've just 'dealt' with it. I'll very seldomly get a p440 but it has been months. If I had to guess its the check valve.

previously, other family members who were driving my t4R at the time had the filler neck and the charcoal canister replaced in an effort to troubleshoot this.

I think working from home for the last 1.5years has diverted my attention elsewhere as I fill up so infrequently at this point, but the check valve is where I am going to go first if I ever am filling up the tank multiple times per week again.

Standing out in the 20 degree weather while holding the gas pump trigger at a very specific light-pull in an effort to not get the pump tp pop is very annoying.

 

[phattyduck]

No I'm in Colorado and our pumps are pretty basic. But I was planning on driving to CA and am aware of their pumps so I'm worried I may not be able to get gas at all.

You do know that there are millions of us here that fill up our cars/trucks regularly, right? :

The 01/02 trucks are more susceptible to evap issues, since the evap system got moved under the body instead of higher up in the engine bay. Overfilling can cause evap problems there that don't happen on the earlier setup.

-Charlie

 

[MaineRunna]

The gubmint mandated onboard vapor recovery around 2000 meaning that the vapor in the tank can no longer be vented out through the top of the filler neck into the atmosphere when you are displacing it by filling up with gas. It now vents into the EVAP system whichis much more complex and has a bunch of hoses, tubes and valves. It is most likely the canister causing the problem. There could be charcoal pellets from the canister plugging other parts of the system though. (Big problem in Hyundais, not sure if the canisters breakdown and contaminate the rest of the system on 4runners)

 

[fourfive]

2001 4runner sr5
I don't have the P0440 code, (could've been cleared by previous owner though. Bought the truck a few months ago) but I looked at the link you posted and may go ahead and check charcoal cannister and check valve if I don't find anything wrong with my filler neck.

When you had the issue did you notice any pressure or gas coming back up the fill neck? It's hard to tell but it almost seems like when I pump gas at normal speed the gas isn't able to run down fast enough causing the shutoff.

I didn't notice any gas coming back up the fill neck & if there were any pressure differences, it wasn't anything extremely obvious.