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-   -   Okay, this is weird! Fuel tank rejects fuel. (http://986forum.com/forums/showthread.php?t=58136)

Retroman1969 08-01-2015 08:21 AM

Okay, this is weird! Fuel tank rejects fuel.
 
The daily driver was empty this morning after doing a long trip yesterday so I started to fill it up at the station and the pump kept cutting off after just a few seconds. I pulled the nozzle out and fuel bubbled like a cauldron in the filler opening then sprayed out like a super soaker. I tried to pump one more time and the same thing happened.
What the blinkin' hell??

I gave up and switched to my other car

What could be causing this? I've been smelling fuel in the car on occasion recently. A clogged vent? Does this car have an electric vent pump or something?

Thanks!

911monty 08-01-2015 08:27 AM

Man I'm learning a lot from your car!! LOL. There is a fuel tank vent valve under the right fender liner that I think is the problem. This is where the carbon canister and fuel tank vapor recovery system is located. Not an uncommon occurrence on mellow aged cars. If you've been smelling fumes then look into this system and check hoses on top of fuel tank for leaks.

rick3000 08-01-2015 09:06 AM

I had the exact same issue a number of years ago. It was repaired under warranty, and I was told it was a slipped hose, that had to be reattached. Unfortunately, the invoice I have did not mention specifics, but there is a TSB related to this exact issue: Link There are also a number of threads on this, if you search, 986 fuel not filling, here and on RennTech. :cheers:

particlewave 08-01-2015 09:32 AM

Like Rick said, this is a very common issue. Mine used to do it all the time, but fixed itself. :p

CraigM 08-01-2015 04:25 PM

I had this when I lost my fuel cap on a road trip, and the only cheapo auto store replacement didn't keep a tight enough seal.

How's your cap?

Pro-tip I found somewhere online at the time to get me home: there's a little button thingy right next to the filler hose on the car that our ignition key can push. Supposed to be pushed by the gas cap. Anyways, push that while you pump slowly and you can at least fill up to get you on your way. Getting home and putting a proper cap on it solved the issue.

thom4782 08-01-2015 06:21 PM

There are two symptoms. They may be related to a single problem or you might have two problems.

The fuel smell suggests a leak somewhere in the EVAP system. It could be a crack in the top of the tank gauge to a worn o-ring in the fuel cap or any of the hoses connecting things to the charcoal canister. Is the fuel smell always present or just when you fill the tank completely. In my case, it was there when the tank was between full and half full. This turn out to be the tank gauge.

The hard to fuel problem can have several causes. As one poster mentioned there is a TSB associated with a hose slipping inside the tank. Or it could be a plugged carbon canister. In could be literally anything that keeps the fuel system from venting as the tank fills with liquid. BTW: There is a shut off valve associated with the carbon filter. And sometimes, it can be just the pressure in the hose from the pump. If it's high like it is at some stations, air can't vent quickly enough and the pump handle clicks off. In my car, I both re-tied the hoses in the tank according to the TSB (actually the shop did it) and I replaced the carbon canister on my 14 year old DD. I did these at different time and the slow filling problem got better with each fix. Now its fixed completely

Hope these ideas help

Retroman1969 08-01-2015 06:32 PM

Thank you so much for the input guys!
I'll check all those things. The cap appears to be fine, though I should probably replace it just for good measure due to the age and mileage of the car. It is pushing down on the tab-thingy when it's tightened down, though not much. The tab seems not to spring back up very well when cap is loosened.
I now remember I was shown the valve unit in the right fender awhile back as a possible culprit for the fuel smell. Another thing to check and possibly replace.
Checking the link to the TSB now. ;)
Thank you again! I'm about to go try to fill it again now that it's dark and cool, and it has been sitting all day.

Retroman1969 08-01-2015 06:36 PM

PS: the fuel smell is intermittent. And it doesn't appear to matter how much fuel is in the tank. It's very odd. It can't be smelled outside the car only from the passenger compartment.

Retroman1969 08-01-2015 07:00 PM

Just got back from the gas station.
It was just doing the same thing as this morning. :(
But, CraigM, I tried your little trick of pushing the little spring-loaded tab in with my key while pumping and it pumped gas just fine! After about a half tank I released the tab just to see what it would do and it allowed me to fill the tank the rest of the way without any problems. ;)
The cap is original and factory, so I'm wondering if it's just worn or not seating properly.
What does that tab-button next to the filler do exactly? Open a vent?
Thank you guys again, and thank you Craig for your tip. ;)
My mechanic is back logged, so will get a new cap from the dealer for now and see if it fixes it. If not, I'll have everything related to the vent system looked over for condition, starting with that vent valve (it seems to come up often in similar discussions).

thom4782 08-01-2015 07:56 PM

Check this Youtube video. https://www.youtube.com/watch?v=zulI06TPBVc. Perhaps the key trick forces the valve to open.

Retroman1969 08-02-2015 06:34 AM

Cool! Thanks for the link. It must be fairly common to have a video on it. Time is always the factor for me, but I might give it a shot if a new cap doesn't fix it. ;)

I'm hopeful that this and the gas smell are related, but I may have to tackle these issues separately.

NewArt 08-02-2015 07:25 AM

The refusal to fill problem is almost certainly caused by the absence/misplacement/misfunction of an electro-magnetic "pill" which is attached to the valve on the filler tube found under the fender liner. This gizmo needs to be operational and in place in its slot in the pink and black valve. It senses the opening of the metal filler flap when you insert the gas pump nozzle and allows the fuel to pass.

Jake Raby 08-02-2015 08:21 AM

The ORVR valve has failed. This is what vents the tank during refueling.

Retroman1969 08-02-2015 05:44 PM

Thank you Newart and Jake! If I don't have time to swap this part this week I'll have it done when it goes in for its oil service and checkup on Friday (and also check the top of the tank for any leaking hoses or seals).
The original part only lasted 145,000 miles! What a piece of crap! ;)

cesarpeji 09-12-2016 04:01 AM

Jake, on my 06 S. where exactly is the vapor canister and how to remove it. The 986 boxster was located on passenger side wheel well.. thank you.

PaulE 09-12-2016 06:59 AM

There is also Fuse E6 which controls the radio and a solenoid valve on the fuel system. If the fuse fails the tank can't vent and can't get filled. (just in case it wasn't the previous answer!)

dak138 05-04-2020 03:05 AM

Hi all. I've had a fuel filling problem on my car since I've had it. Investigation showed the the bleeder valve under the filler does not have the magnetic reed valve in it so I've ordered one.
My question is where does the reed valve/osvr contact connect to the car? I've hunted all around the wheel arch and can't find a connector?
Very grateful for any help - this is proving to be a nightmare!


Sent from my ASUS_Z01KD using Tapatalk

Rob175 05-04-2020 06:22 AM

My 98 fills "OK" except at the very end of the filling process. I can fill the tank up but when I get to the point where another gallon COULD BE added I have to stop and let a few big "bletch" sounds escape before I can start topping off and finish.

IF I were to simply end my fueling at the first auto shut off by the pump I'd probably be shorting myself by at least 2 to 3 gallons. I do know that there is a danger of filling up the canister by overfilling but I'm not doing that......it just needs a few seconds to "bletch"....lol

I consider my situation to just be one of those "unique" Boxster "features"....LOL

outsidetheboxster 05-04-2020 04:59 PM

I tried adding gas to mine from a gas can with the car sitting static in my shop with the battery disconnected. No go that way either. What a mess! Have to depress the little tab next to the fill cap. Then it went right in with no issues!


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