Can't fill Gas Tank suddenly -2005 Prius

Try another gas pump

 

I second that. Had this happen exactly once, with an oddly shaped nozzle at a station I had not visited before. Been back since, used other pumps, with more typical nozzles, and no problems at all.

 

welcome!
pump as slowly as possible, try turning the nozzle 90 and 180 degrees.

the bladder is a rubber container inside the metal tank that holds the gasoline. sometimes they are just old.
cold temps are what have a detrimental effect on capacity, not hot.
to fill with a gas can, you need one with a nozzle small enough to penetrate the check valve

 

So what's best for this never letting the car sit on empty longer than a few minutes feel it right back up expand the bladder try to keep it that way IE like with a full tank? As of now I can still fill up till it shoots out the overflow and it will gurgle if I catch it just right it'll gurgle and not come out of the car or out of the well or out of the filler hole but it's 300k it's not getting any more pliable that's for sure.

 

Some newer Costco pumps do this. I have to make sure the nozzle is pushed in fully and held in place. PiTA.

 

Now see I fill up opposite nozzle barely in opening . Like as in less than inch of silver nozzle in the opening hole after door to tank is open .I'm on first click on speed rail . I get to approx 8.5 gallons at first cut off . I hand feed to 10.4 gal. At less than 1 click setting on rail . This has taken approx 4.5 min at Sheetz blue fuel ..

 

You mention "suddenly" in the thread title. The story here may partly depend on how "sudden" the change was.

Refueling with the bladder tank is always a little bit finicky, takes less fuel in cold weather than warm, and so on, but that behavior doesn't really change "suddenly". If you've had the car for a while, you should be pretty familiar with what that's normally like.

The car also has a kind of complex "onboard refueling vapor recovery" system that can be damaged or malfunction. When it isn't working, it can absolutely cause back pressure that shuts off pump nozzles (and sometimes even belches fuel back out). If you've really noticed a "sudden" change (and you've tried a few filling stations to rule out just one bum pump nozzle somewhere), then it could be that you're not just looking at the old familiar slight finickiness of the system, but an actual ORVR problem that can be fixed.

On the topic of ORVR problems, some of the well-meaning advice being given in this thread carries a strong risk of causing ORVR problems eventually. Toyota explicitly warns against doing things like pumping extra slowly to force more fuel in after the normal nozzle shutoff. We had a thread a couple years ago where one member had a car that wouldn't fill, eventually got the ORVR system fixed and reported back "I am confident to say the the problem is resolved", got repeated advice from several other members to stop doing that stuff that messes the system up, never stopped doing it, and started a new thread several months later about that cussed ORVR system needing repair again.

 

I put 10.5 to 7 gal at every fill . Every fill. Summer and our winter . Sheetz blue. Usually about 508. To 530 showing . Square flashing for 12 miles .

 

It’s also good to know that the pump shut off system is measuring the volume and speed of the air coming out of the tank as it is filling. In the case of a bladder tank there is very little air returning while it fills ( think of filling a plastic bag ) that is until you reach the filling stem. Then the volume of air increases rapidly shutting the pump off.
As you might imagine gas with a lot of air mixed in would also do this, high volume gas stations are known to have lots of air in the gas you buy, I had one chemist say it’s best to get gas early in the day to get the best volume for your $$.

This is why a cool / stiff bladder can fake out the pump. It thinks it is full when it isn’t.
I believe a bit of driving, sloshing the gas around, adding more etcetera helps the bladder lay itself out.


iPhone ?

 

I have started to have bladder issues it seems.

I get the symptom lately where it goes from 3 pips on the gas gauge to 1 pretty quickly and when I refill it takes about 4 gallons and reports back full or close to full.

I live in NJ, so I have limited options on filling my own gas. When it has happened the attendents don't care if I fill with the pump upside down, but I am not sure I should be that hands on... I also cannot stop them from topping off. I read somewhere else that can cause issues. You learn something new years into owning a car.

Can anyone expand on the fixes for this issue? I feel like I had it happen, then it got better and now it is consistently bad.

Does the person with limitless energy and cash to spare replace the entire tank?

 

That is very bad news about the attendants. It's been decades now that cars have complicated evap and ORVR systems that you can knacker by topping off. Not just Prii, by a long shot. If there's anybody who should have been trained on that fact, you'd think it'd be filling station attendants.

Maybe they do get trained on it, but they get worn down by all the motorists saying "how come you didn't top off my tank???".

Filling a Prius can be a bit finicky even normally, but if it has suddenly changed and become a lot more finicky, that likely indicates a problem in the ORVR system that can/should be fixed. More in post #11 in this thread, and the other thread linked from there.

Not all of the ORVR system is in the tank itself, so just replacing the tank isn't a guaranteed fix, depending on where the problem is. So the bad news is somebody might have to work out where the problem is. The good news is, once worked out, it might not require the whole tank.

 

I don't think anyone thinks that topping off the tank is bad... Also I have been places where the push the total to a round number even though I am paying with credit. LOL.

I was hoping to find the most likely candidate part that could have gone bad, but I don't know how many people have had this fixed. There at least is good info out there. Now I just need to put in the time to figure out how this system works... if I can and maybe take action.

One negative about this repair is it that it is guaranteed to take place on your back under the car.

 

Yeah, that's the problem. I mean, they could go straight to Toyota's FAQ:

Can I “top off” when I’m refueling my vehicle?

"Topping off" or trying to squeeze in additional fuel once the gas pump has clicked off is not recommended. It can cause damage to fuel or emission system components.​

but, instead, a lot of people just keep doing it.

You can find a lot of that info upthread in post #11 and the older thread that it links to.

In that older thread, the problem got fixed by replacing the fuel filler neck (and the ORVR components that are mounted on it). That might not be what fixes your case (those aren't the only ORVR components that can get messed up). But you'll see the basic techniques you'll need to pin down where your issue is.

That older thread led to the original poster saying "I am confident to say the the problem is resolved." Regrettably, the original poster couldn't be talked out of the topping-off habit (despite the efforts of several members in that thread), and ended up starting a new thread eight months later reporting essentially the same problem again.

 

ChapmanF, thanks for your information here and your research on this in the past. I did notice the unwillingness of the other poster to stop topping off the gas tank. Shouldn't be a tough habit to break. I have a new rule, fill on thee pips and don't top off. Even though I can't fill my own tank in this NJ, I can at least decide when to fill and will ask not to have it topped off. (seems like topping off even here is an infrequent occurrence, so maybe the word is getting out).

I will also see how accessible those two valves are from under the car. I have a local scrap yard that I pull parts from and I might consider taking those.

If I ever get around to replacing one or both of those valves by the filler neck and I get some relief I will post back here.

 

In brief googling this afternoon, I saw news releases that topping off was prohibited in Oregon back in 2009.

 

Topping off is definitely a thing I did in the past and until looking into this issue, didn't understand could cause problems. I consider myself pretty mechanically inclined compared to most people I associate with. I always do it when returning a rental car... just so I don't have any issues returning it full. LOL.

I took a look above the driver's side rear wheel well and there is a plastic cover for the filler area. I am starting to think that replacing these valves may in fact be somewhat painless. There is no way I am dropping the tank. Done similar work before... not fun. If the one $40 fuel shutoff valve fixes the issue it would be money well spent. I may have to investigate more as time allows, but access may not be a huge issue... I can hope at least.