Evap system/ difficulty fueling

[Clinton Ellyson]

2005 Yukon Denali XL. Slow refueling. I've replaced the usual culprits, the evap solenoid/vent valve and the canister, and yes there were pellets in the line going to the gas tank. I shook it out, but didn't remove it or blow any compressed air through it.

I say all that to ask this. Without dropping the fuel tank, can I take the line coming from the tank leading to the canister and use a shopvac to suck that line and the vent clear? Has anyone tried this or will I need to go ahead and drop the tank?

 

[treehan77]

You can try shooting compressed air in the lines, I got ALOT of pellets out that way. I WAS able to fix the slow fill up that way.

I still had a EVAP code come up every once in a while. I eventually dropped the tank - there were some pellets I couldn't get out in all the lines on top of the tank and in the tank. I replaced the pump while I had the tank down. It's not too tough to remove really, so long as you run it almost out of fuel. I did it by myself in the driveway. Truck on ramps and used the jack to lower it.

 

[treehan77]

I had pellets even up in the purgevvalve on the I take manifold. You can clear that line with air, but They kept coming after I drove it a while.

 

[treehan77]

Oh and be SURE your new EVAP vent valve actually works. I put on a brand new account Delco unit. Defective! Had to get another, than my code for small leak went away (also will say tighten fuel cap all the time). You can give it voltage and make sure you cannot ow through it with voltage applied. The original and the first replacement I could, finally got a good one and it sealed.

 

[ivin74]

If you don't wanna drop the gas tank you can take the driver side rear seat and cut a hole on the floor panel disconect the lines at the fuel pump and blow them from there. Thats what I did, now I have a access door to the fuel pump.

 

[Cyclemoe]

You can use a shop vac on the lines. I did that with my sons tahoe and cleared them. I also disconnected the purge lines at the tank and blew compressed air from the intake back. Make sure you have a tight connection on the vacuum. Shake the lines as you go also. You’ll know when you have the lines clear when you see the tank start sucking in.

 

[Clinton Ellyson]

You can use a shop vac on the lines. I did that with my sons tahoe and cleared them. I also disconnected the purge lines at the tank and blew compressed air from the intake back. Make sure you have a tight connection on the vacuum. Shake the lines as you go also. You’ll know when you have the lines clear when you see the tank start sucking in.

That's what I needed to know. Thanks

 

[Clinton Ellyson]

Oh and be SURE your new EVAP vent valve actually works. I put on a brand new account Delco unit. Defective! Had to get another, than my code for small leak went away (also will say tighten fuel cap all the time). You can give it voltage and make sure you cannot ow through it with voltage applied. The original and the first replacement I could, finally got a good one and it sealed.

I've replaced mine, but later read somewhere about this same issue. I'm going to go ahead and make sure the lines are clear and if that doesn't solve the problem I'll revisit the vent solenoid.

 

[Clinton Ellyson]

If you don't wanna drop the gas tank you can take the driver side rear seat and cut a hole on the floor panel disconect the lines at the fuel pump and blow them from there. Thats what I did, now I have a access door to the fuel pump.

I did that to an S10 I had when the fuel pump went bad.

 

[Clinton Ellyson]

Just an update. I used electrical tape and connected the vent hose to the shopvac and it did clear the line and refueling is back to normal.

When you use this method you're going to not only see the tank cave a bit, but you'll hear it. Scared the crap outta me and I ain't scared of nothing. You should also do this in a well ventilated area because you're going to get some fumes and of course no where near an open flame. You should also open up your shopvac to let it air out after you're done. You know it's been a while since you've cleaned it out anyway.

Anyway, this saved me from dropping the tank. Worked for me hope it works for you.