Gas only filling to 3/4 of a tank

Ive searched around for answers but can only find info on older 4runners

So it happened once before when the pump shut off at 3/4 of a tank, i originally thought nothing of it and next time i filled up all the way. Until yesterday, i was driving up to Norman OK. at two different gas stations I could only fill up to 3/4 of a tank. On the fist occurrence my gas gauge went down normally. However on the second occurrence my gauge dropped a quarter in under 60 miles. Then was able to fill to full.

So my question is what could be causing it. My guess would be if there is a sensor in the neck is is going bad, or what i think more likely it is is the fuel evap. system. I think I have air in the tank causing it to think its full, and sometimes it escapes which would explain a sudden drop on the gauge and why sometimes I can fill up to full. Im just wondering how this stuff could go bad on a 16.

 

Continuing to fill the tank after it clicks off will fill the evap canister with fuel. Then it can't vent the air in the tank the next time you fill up. Don't top off your tank after it clicks off.

 

I had. 2011 Optima that did this intermittently since new. I often could not completely fill the tank before the auto shutoff. Usually would shutoff at 3/4s My guess is evap problem too.

i never took it in because it didnt happen all the time

 

Never do, whenever I filled up before this happened always stoped as soon as it clicked off.

 

I am not sure if this is the same issue or not, but I had an issue with my Tundra where I could only fill up for a few seconds then the pump would stop as if it was full. The dealer claimed something had hit and damaged part of the tank. I ended up having it replaced under warranty.

https://www.tundras.com/threads/issue-refueling.18777/

 

Update, im not sure if its normal. I opened the gas tank while the truck was running and loud electric motor stated in the nozzle area. I know from searching a lot of people report a noise and it is the the evap system. Not sure if it suppose to run when on, i thought it runs 5 hours after ignition is turned off.

 

I own a 2007FJ as well as my 2019 Pro. Both do the same damned thing. Pump will click off, then I'll nurse it and get another 2.5 gallons out of the pump. Yes, I've heard the warnings about the evap canister being damaged. I've had my 2007 since 2010, and the 4Runner since new since March 2020. I hate filling up, so I always try to pump as much gas as possible. Never had an issue to date. Yes, the possibility of contaminating the evap canister makes sense.....but I've never had that problem.
And I've filled the tank to the point that fuel was dripping out the filler neck.

 

Very true! Can eventually cause costly damage as well.

 

this may or may not be useless since a different platform, but I have an 06 Chevy Trailblazer that did the same thing. there are two evap related solenoids on the chevy, one near the gas tank and one by the engine. I took a shotgun approach and replaced both and it fixed the issue.