GMC fuel tank not filling up

[Wildfowler]

Try this at your own peril!! I'm sure you could damage your vehicle if you don't know what you're doing.

I have endured this problem for about a year now. It's gotten to the point where I have to go the same exact pump each day to fill up before my tank is even close to empty because it takes so long to fill up.

Put pump in tank, squeeze handle, fuel flow starts and almost immediately clicks off. Repeat. Squeeze handle, fuel flow starts and almost immediately clicks off. Repeat. Repeat. Repeat. Repeat. Etc. etc. etc. etc. etc. etc. It might literally take over ten minutes to completely fill up an tank from empty.

At many gas stations if I put the nozzle in about halfway and pry upwards it seems to ventilate the fuel tank better allowing the pump to operate somewhat normally and may only click off five or six times instead of 40 or 50 times.

I have found that cappys gas in Ridgeland the kangaroo in Winona will fill me up without clicking off. I don't know what is different about those two gas locations but virtually any other place I stop causes the problem.

Then I decided to ask google about this. Turns out there is a reason and an easy cure for this.

The reason is the EPA garbage associated with clean emissions and save the whales and who knows what else. There is some sort of fuel vapor accumulator, flux capacitor or underneath your vehicle near the fuel tank. If you drive down gravel roads every day like I do you're more likely to have dust get captured and clogged up within the system. If dust clogs up the system believe it or not your fuel tank won't be able to ventilate itself adequately while filling up forcing the fuel pump to click off every three seconds, forcing you to go bald from pulling all your hair out like I have.

I found this nifty little video online and decided to give it a try.

Of course as usual, I decided to give it a try way out in the middle of nowhere just in case I couldn't get it put back together correctly it might actually leave me stranded instead of from the comfort of my driveway at home.

Luckily this was very easy and did work for me. I chose not to completely remove the box and bang it around like he did in the video, I just crawled under my vehicle from the driver side, found the flux capacitor and removed the three hoses that were attached to it and used my air compressor to blow out the dust from the fuel side.

Do this at your own risk and peril!! I'm sure it would be possible to damage your vehicle if you don't know what you're doing.

[msudawg8087]

What make and year model GMC are you workin with here?

[Wildfowler]

2012 Sierra. 5.3 liter.

[Bercy]

My Toyota Camry does that - maddening.

[deltadukman]

I think it has more to do with the pump handle than the vehicle. I've just now started noticing it lately and most you can tell are newer pumps.

[Wildfowler]

I agree with that a little bit. That the handle can click off occasionally. But not at the rate of every half pint or so of fuel being dispensed. Depending on where I go, it may click off once or possibly twice. But not 85 times during the period it would take to dispense 20 gallons or so of gas.

The biggest problem I can see is the hose that connects your fuel cap to your fuel tank is about 1 mm diameter larger than the fuel nozzle itself and there's nowhere for air to ventilate through that hose. Air has to escape from the tank through the flux capacitor that was clogged with dust.

When I blew my flux capacitor out a huge plume of dust jetted out of the other port just like in that video.

Also about a week later my check engine light went off. AutoZone had previously told me it was P442 (I think) and is related to those components I blew dust out of.

And to be fair, while looking around underneath my vehicle, I noticed there is a secondary smaller flux capacitor that one of those three hoses is connected to it. I apparently had a limb or something in the road knock the hose completely off of that secondary flux capacitor. I put it back together and a few days later my check Engine light went away. Probably because I replaced the hose to that secondary flux capacitor?

Anyway, I can now pay at the pump, begin pumping, use the lazy latch and walk inside the double quick for a bag of ice and come out to a full tank of gas.

Which is nice.

[stang67]

I have a 2010 5.3. I have to peepee the handle to the side to keep gas flow going a lot of times. A few years ago, some sort of vent canister was giving a check engine light. I wish I remember the details, but replacing with the 2010 part was hundreds of dollars. I read online that you could use an older part for like $30. I did and it's worked so far. Knock on wood.