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Fueling Problem

This problem has become worse and worse over time. When I am fueling my car, the shut off is triggered, clicks off and fueling ceases. I used to be able to hold it, slow the flow down and fill my tank ever so slowly. Recently, it trips almost instantly. I would guess that it is a venting problem. What do you all think?

Yup. It’s a venting problem.

Since You’ve not told us the year, make, amd model off the vehicle, I’ll just post the description of my own system to illustrate my explanation.
http://tijil.org/Scion_Docs/Scion_06_misc_docs/2007sciontc_ncf%20Folder/2azfeemi.pdf

Basically, as you pump gas the fumes from the tank are sent through an activated charcoal filter to capture hydrocarbon molecules and then to a vent near the fill pipe. The captured hydrocarbon molecules then get sucked into the engine intake when you start the car.

If the diaphramatic float valve is stuck or the charcoal bed in the canister is saturated (often from “topping off” the fuel tank), than the vent path will be blocked and the pump will detect that as if it were a full tank.

If your car is post-1996, check the ECU for any stored codes. You might get lucky.
If not, you’ll have to bring it in and have it diagnosed.

Try different filling stations. There are a number of filling stations in my area that cause your exact problem. And there are some that allow super fast fuel fill ups.

Don’t ever do this! (turn the nozzle upside down)… The risk is a fuel spill…Use the search feature of this board “slow fill” There will be dozens of threads and posts…

Echoman here. Thanks for your replies. Vehicle is a Toyato model: Echo, year: 2000.

I have a Chevy Avalanche that does this at certain times. It is maddening considering how big the fuel tank is (31.5 gals). It has no problems with the evap and has done this since new. It happens at certain gas stations during the transition from summer to winter fuel or winter to summer. If it happens, give up and change stations. Life is too short to take 45 minutes to fill the tank (sorry, you electric car owners). Changing stations alters the blend of gas additives or the mix of summer and winter in the tanks at that time. Certain brands of gas seem to be much, much worse than others. If the evap is OK, change stations and that should help. I haven’t found another fix.

Mustangman, did you have this checked out when the Chevy was new?

I’ve had this problem occasionally with my truck. Personally, i believe it is a problem with the vapor recovery system at the station. My fix is to pull the nozzle out partway to disengage the vapor baffle. It usually fills without issue. But, I haven’t had any problems in the last couple of years. And have done no repairs to the evap system.

Here’s some reference info that may be helpful.

http://www.agcoauto.com/content/news/p2_articleid/294