2011 Sierra wont take more than 7/8 tank of gas???

[Mekanik]

Hey guys, I myself am a young and learning gm technician. However, my personal truck is stumping me. It is a 2011 Gmc Sierra 1500 5.3 flexfuel with a 6" lift. The previous owner was a coal miner, but the trucks appears to have been immaculately maintained and not seen gravel roads. I bought the truck after it was involved in a rear end collision that bent the last 12" of frame rail. I straightened the frame and bed side, put on a new bumper and hitch and have been daily driving it. Now that you know it's history, I'll tell you my problem. When trying to fill up the tank, it gets to about 7/8 of a tank and clicks off. If you go very slow and allow the fuel to gurgle down, you can fill it up. I do not believe the float arm is bent or reading inccorect as the filler neck is not filling up. The gas does eventually gurgle down. With most of the evap issues ive seen, they wont take gas at any level. However, i crawled under the truck and unhooked the evap line from the tank to the canister to eliminate the possibility of a stopped up cannister or vent valve and the issue remains. I have visually inspected all the evap hoses and see no pinches or kinks. I blew air into the canister vent line and could hear it escaping through the filler neck. So im stumped. I dont appear to have an evap blockage but it also doesnt appear to be completely full. Am I missing something here?

[Jsdirt]

Well, seeing how my Silverado continuously clicks the pump off at any level, and has since it's first fill-up, it might be considered "normal" for these things ....

 

Some pumps go no problem ... and others will click off every 2 seconds from the instant I pull the trigger, sending me into an angry frenzy. I can fiddle with the pump and get it in just the right position so that it will fill the truck up ... but MAN what a pain in the ass!!

 

If it's this bad in a truck that's never been hit, I would think that after a big hit, any tiny little kink in any part of the filler tube would wreak havoc.

[MikeNH]

I've only had one station that did that with my truck. OP, have you tried a few different stations?

[Mekanik]

Yes, ive tried 3 different stations plus a nozzle/pump at my house

[Mekanik]

The truck wasnt hit hard enough to interfere with any of the fuel/evap equipment. And as someone who's been around hundreds, if not thousands of gm fullsize vehicles, this would be the first to act this way without any perceivable issues.

[Fla Eagle]

Well, seeing how my Silverado continuously clicks the pump off at any level, and has since it's first fill-up, it might be considered "normal" for these things ....

 

Some pumps go no problem ... and others will click off every 2 seconds from the instant I pull the trigger, sending me into an angry frenzy. I can fiddle with the pump and get it in just the right position so that it will fill the truck up ... but MAN what a pain in the ass!!

 

If it's this bad in a truck that's never been hit, I would think that after a big hit, any tiny little kink in any part of the filler tube would wreak havoc.

I have had the same issue with my truck since it was new. Very few gas stations I have been don't make me hold the nozzle at just the right angle and speed. This will really piss you off when you're in a hurry.