Gas pump keeps shutting off

I haven't had any problems with the pump not filling at all, but I have had troubles with over/under filling, and it's highly pump-variable. From your description, it sounds like a pump-specific problem, but related to the bladder. You were probably just getting an air lock and the pump couldn't deal with it. My advice would be 1) don't use those specific pumps again and 2) if you have this problem again, try ensuring that there is a gap for pressure balance and try filling as slowly as possible at first. Once you get it filling make sure that you gradually push the nozzle down so that you don't have spillage. If that makes it cut off, just put in less gas than you possibly could have used (4-5 gal or so) and use a different pump next time.

 

Hello, priusblue,

There are many threads on this site that address this problem. It sounds like you have a Gen II ('04 or '05), yes?

I have the same generation and the same tendency to have difficulty with filling. I find myself seeking out the older, slower gas pumps, which alleviate the problem. The theory is that the bladder that lines the tank is somehow responsible for this. Theoretically, the bladder expands slightly under the pressure generated by too-rapid filling combined with inadequate venting. Then the tension from the expansion causes the bladder to 'exhale', thereby shutting off the pump. If quite full it may also exhale fuel!

Your manual will tell you that the volume in the tank will vary considerably with temperature due to the bladder. The volume decreases with decreasing temperature.

Enough people have had difficulty with this that a Technical Service Bulletin (TSB) was issued by Toyota to correct it. I think the main goal of the service was to address peoples difficulty filling the gas tank. A TSB is not a recall. You generally have to initiate the servicing by requesting it, but it is free of charge. If you use the Search function (upper right of the page) and put in "Gas Tank TSB" you should be able to get the specific info. This would include whether you VIN is covered by the TSB. I think the work was fairly extensive, involving replacing the filler neck and re-flashing the appropriate ECU.

My VIN was not included, so having this done was not an option.

Good luck,

storm petrol

 

Sorry, priusblue!

I meant to be addressing patrickmaher.

storm petrol

 

it is VERY important that you keep a tight seal while filling your tank. otherwise, you will greatly increase your chances of spilling gas. to me, it sounds like its a pump problem.

you say you are able to fill the tank successfully on occasion. that tells me that there is mostly likely nothing wrong with the car.

i blogged a post on this with a detailed explanation from an expert gas pump jockey sort of dude. actually, he is a professor at scme college...but he sounds like he knows what he is talking about and pumps need that tight seal to work correctly.

 

*None* of my previous vehicles have ever had a tight seal on the filler and they all worked perfectly with every single nozzle.. The Prius *does* have a tight seal and is a pain in the butt to fill up sometimes.. Hmm.. I think the professor has a disconnect between theory and practice...

I've found that only putting in the very tip of the nozzle increases the chances of an easy fill, but every time I fill up, I still think seriously about taking an X-acto knife to that rubber gasket around the filler opening, which would make the car like every other car out there except for the variability of the bladder, but I believe you should be able to get a truly "full" tank consistently without the gasket. Yes, fill-up emissions could potentially increase, but use of vapor-recovery nozzles should take care of that..

 

that gasket is to help prevent splash back

 

Lots of gas pumps are not well maintained. Can you just keep using the one you found that works well?

 

Copied the following from a post made not too long ago. The original discussion was on the old version of PriusChat. See this post

"As indicated there are some previous posts on this subject. I believe this is different than the cold bladder problem that may reduce the volume of a complete fill up. There are two suggestions that I recall. One was to lift the hose to be sure the vapor recovery portion did not contain overfill from the previous user. Supposedly, lifting the hose drains any residual gas that might cause early shut off. The second was to turn the nozzle over while filling. I have had this problem occur exactly twice in about 18 months. The first time I was clueless and just spent 10-15 minutes to short pump 6 gallons in an empty tank. The second time, I did both of the above and was able to fill the tank without further problem (except struggling to keep the nozzle inverted). I haven't had the problem for quite some time so maybe bladder seal in the fill tube loosens over time, reducing the problem"

 

I have the same problem. 07 model. I did not have the problem during first winter, but this year two fill-up & both times I had to fill very, very slowly. I am in northern NM & it seems to be worse when the weather is cold.

 

I have the same issue on my '08 purchased this summer. Sometimes everything works fine, but at others pumping stops immediately. I find if I pull out the nozzle a little bit (not too much) I can pump freely and autostop still works.

 

This has been discussed forever here. I have learned with my 07 to let it air out a little before fueling after my first gas belching episode. The zero fuel vapor emissions mission and the fuel recovery system on this car coupled with the plastic bladder has made this car very hard to fuel. Try this and you will have no more problems:
When you go to the gas station open the gas fuel cap. Leave it open without the gas pump in it and go inside for a bit. Those few minutes of tank venting will allow the tank to breath and expel trapped air and allow the bladder to relax. By the time you come out it will be good to go. Stick the pump in it on very slow fill and hang the pump up on the first auto click off and your fueling troubles will be over. I have cut a piece of wood 1/2 inch wide to jam under the pump handle which pumps very slow. It now clicks off on a full tank first click. Perfect.

 

I got my Prius this September. So far I've only had to fill it up 9 times, and until yesterday every time but one I've had this problem with the first gallon or two, but then it would settle down and I could fill normally. But yesterday's fill up was an exercise in frustration and anger - it would only pump for a second without shutting off no matter how slowly I filled. It's the first time I've filled it up in below freezing temperatures, so I wonder if that is the problem.

I tried various combinations of pumping very slowly with the nozzle fully in, partly out, twisted to one side or the other. I even tried pumping with the nozzle not through the restrictor at all, and the gas was going down through the hole at first but after a second a big slug of gas came shooting out. All in all, I spent about 15 minutes at one gas station getting ~4.5 gallons, and then another 15 minutes at another station getting another ~4 gallons.

Every other car I've owned, including two Corollas, has had a hole in that restrictor plate for air to come back out. I assume that the Prius supposedly doesn't need it because of this flexible bladder people have been talking about in this thread.

My wife's 2005 Prius doesn't have this problem. Is is possible that my car's bladder isn't flexible enough?

 

YOU MAY HAVE SUGAR IN YOUR GAS TANK!!! I just found this out because my car did the exact same thing yours did. I took it to the shop because my car kept stalling. See if someone will take a look at it for you. It may cost you about $100-$200 to fix it.

 

This thread is about filling issues, not stalling engines.

Tom