Can't Fill up with Gas - Nozzle Clicks too Soon

Hello all. I tried filling up my Tacoma ('03 Xtra Cab V6 4wd) today and the pump clicked after only pumping ~3 gallons. Tank was only 1/4 full or so when I got to the gas station. Truck is running great, idling fine and throwing no codes (scanned it twice to be sure).

I've done some reading that suggests a vent valve on the charcoal canister itself, or another under the hood, or something wrong with the filler neck.

Where ought I begin my troubleshooting and diagnosis work here? Problem just began today.

 

What we used to do on capable vehicles with the engine running to test the system integrity was to command the purge valve open then vent valve closed then monitor tank pressure to see if the tank starts to pull a vacuum then keep the vent closed and purge closed to see if pressure builds. I don't know if you have a scan tool that could do such or your vehicle would allow you to do such tests.

In Lieu, I believe you would have to use an emissions smoke machine while blocking the port the nozzle goes into with the cap off and vent port on top the nozzle port open or remove the vent valve and try to gently blow compressed air through it.

I believe with the engine off and the vehicle not running a self test the purge valve should be normally closed and vent valve should be normally open and the fuel cap alone seals the system until you remove the cap.

 

Had this same problem with a 95 Honda Civic I used to own. Would only let me fill up about 2 gallons shy of full. If it sat idling at a light at that fill amount it would start pouring out of the fill valve. Never did figure out what was wrong.

 

Did you try a different gas pump? That happens to me occasionally at the same pump at the Costco gas station I frequent. There are actually two pumps this happens at. I just avoid them.

 

I did try two different pumps at two different gas stations. Maybe I'll try a 3rd tomorrow to thoroughly rule out the possibility that my luck is bad enough to pick two bad ones in a row

 

Your charcoal canister is plugged up. Get a new one.

 

Ok so I'm going to pull the bed off and inspect the charcoal canister and it's assorted tubes before ordering to ensure I get any ancillary stuff I need all one one order.

 

@Blackdawg what did you do to fix this problem on Igor?

 

My grandad had a similar thing happen to him. Turns out topping off the tank is what caused his problem.

GL with repair

 

That sounds right.

Try not to "top it off"

The canister will get full of fuel, instead of vapor.

You don't want that.

 

I've read the same thing about topping off the tank too. I've never done that with the truck, but perhaps previous owner did.

 

Based on your symptoms, it could be your roll over valve (aka fill check valve or vent valve). This valve allows the air in the tank to be displaced when you fill your tank, amongst other functions. If the valve is stuck or not opening all the way, you’ll get issue with filling your tank. The valve is located at the top of the tank. I would also check your hosing between this valve just to make sure it didn’t get kinked for some reason.

Much cheaper to replace than your charcoal canister.

 

Excellent l. Thank you for that info. Do you think it's possible to check without dropping the tank or pulling the bed?

Thinking maybe I can put my borescope up there to lay eyes on things, and avoid either headache (pulling bed or dropping tank).

 

I did this for year with the Civic mentioned above....didn't work out so well.

 

New charcoal canister. Spendy park and a pita to do with the bed on. Have to drop the tank.

But that solved my issue.

And I think I put a new roll over valve in too. I can't remember if I did. I think I did. Can't seem to find photos. I replaced something that was in the tank mount area. And the canister.

 

Thanks for sharing. Sounds like I'll be doing the same except I'll be pulling the bed instead of dropping the tank.

 

Damn tht sucks

I’m with the check/purge valve crowd
If valve stuck, the fuel vapor pressure rises so much that system will not allow u to put appropriate amt of fuel in tank

No Codes?????

 

I have a pretty good memory of replacing the roll over valve and the i know for sure I did the canister.

I don't know if you just need to do only one or the other. I took the position of, if im taking this apart, might as well just replace it all. The valve is cheap, the canister is not.

 

Nope no codes, and running fine

 

Yea im thinking about just replacing the original fuel pump and sending unit too, while I'm in there. If the beds off it's a great time to knock those out as well