Charcoal canister

[iboughtatahoe23]

Changed my charcoal canister on my 2014 because it was kicking the pump off every $5 or so. Now it seems to do it like every dollar. I didn’t blow out lines. I don’t have an air compressor. Could have been the pump. Trying another one now

 

[iboughtatahoe23]

It’s hissing as well. The tank

 

[B-train]

Have you tested the purge solenoid under the hood by the fuel rail? If that's not working, then the engine can't remove the vapors stored in the canister and your tank will back up with pressure and click off the nozzle. Do you leave your truck run when fueling, or shut it off?

 

[iboughtatahoe23]

Have you tested the purge solenoid under the hood by the fuel rail? If that's not working, then the engine can't remove the vapors stored in the canister and your tank will back up with pressure and click off the nozzle. Do you leave your truck run when fueling, or shut it off?

Shut it off. And no, I’m not sure how to do all that, testing the solenoid.

 

[Fless]

Have you tested the purge solenoid under the hood by the fuel rail? If that's not working, then the engine can't remove the vapors stored in the canister and your tank will back up with pressure and click off the nozzle. Do you leave your truck run when fueling, or shut it off?

If the purge solenoid is working properly it is closed with the key off (during fueling). If it's open (defective) with ign off it will let fuel vapors into the intake and flood the engine, causing hard starts.

The vent solenoid in the rear of the truck needs to be open when the ignition is shut off, like when fueling. This is where the "clean" air vents to be displaced by adding fuel.

 

[B-train]

It's on the driver side of the engine, by the fuel line. If you remove it, it should be closed and you won't be able to blow through it. If powered with 12v, it should open and allow flow.

I never shut off my vehicle when fueling. You could try that next time because the engine vacuum will suck on the line and reduce pressure in the vapor system as tank level increases with fueling. If the solenoid is failed closed, then you'll have the problem you speak of.

Luckily the purge solenoid is a cheap, easy fix. Just buy an OEM one or the odds of doing it more than once is quite high (speaking from experience).

 

[donjetman]

When the fuel pump clicks OFF, your done. Don't try to force more fuel in.

 

[Marky Dissod]

Changed my charcoal canister on my 2014 because it was kicking the pump off every $5 or so. Now it seems to do it like every dollar.
I didn’t blow out the lines.

Then you'll likely need someone else to blow out your lines for you.

 

[Fless]

I never shut off my vehicle when fueling. You could try that next time because the engine vacuum will suck on the line and reduce pressure in the vapor system as tank level increases with fueling. If the solenoid is failed closed, then you'll have the problem you speak of.

This is an interesting workaround for a faulty evap system, although if the purge valve is commanded open too far the engine will not be happy -- too rich -- and may stall, similar to the behavior when doing a purge and seal test. And it's not always commanded "open" when the engine is running, so YMMV.

 

[iboughtatahoe23]

Then you'll likely need someone else to blow out your lines for you.

I’m just trying to wonder how it got worse

 

[iboughtatahoe23]

This is an interesting workaround for a faulty evap system, although if the purge valve is commanded open too far the engine will not be happy -- too rich -- and may stall, similar to the behavior when doing a purge and seal test. And it's not always commanded "open" when the engine is running, so YMMV.

I have definitely fueled up multiple times while running and yes, I do notice now when thinking back, that it didn’t click off. And I didn’t notice any symptoms such as stalling or bogging down.

 

[iboughtatahoe23]

Then you'll likely need someone else to blow out your lines for you.

Yay more weekend chores

 

[petethepug]

Oh those charcoal carbon canister pellets. They get in the fuel system like cockroaches. If you haven’t yet replaced your fuel pump, shop RockAuto or Parts Geeks for an OEM lifetime guaranteed unit for about $2h.

Locally or at a dealer they’re about $5h. The fuel tank needs to be dropped and swab’d out of pellets along with the lines blown out. Installing the new f/p & sender is a freebie while you’re tech is in there.

DO NOT use a generic f/p. They fail gradually and will cost you big $ in diagnostics seemingly unrelated to the failing f/p that will be out of warranty. That makes a double ouch for generic f/p replacement.

 

[iboughtatahoe23]

So fuel pump next or blow out the lines? And how exactly do you blow the lines out without ruining crap

 

[donjetman]

So fuel pump next or blow out the lines? And how exactly do you blow the lines out without ruining crap

It's self explanatory when you get into it.
https://www.tahoeyukonforum.com/threads/changing-fuel-pump-sending-unit-bosch.148624/

 

[houstontaylor]

You can just disconnect the tank vent line at the charcoal canister and fill it up. If it works then without shutting off then you know you still have a problem with the system, like with the vent valve or clogged lines.

 

[RET423]

The filter medium from the cannister cannot get into the fuel tank when the cannister fails & the fuel pump has nothing to do with the EVAP system so I wouldn't start changing those parts

The tank vents to the fuel nozzle when filling with fuel, not through the EVAP system, there is a path to the fuel nozzle boot from the tank so air displaced by incoming fuel can escape; if that path is restricted the displaced air can only escape up the fill pipe & cause your symptom

That path is either a small external hose from the tank to the filler neck or a seperate vent contained inside the fill pipe. In either case it vents above where the fuel nozzle releases the fuel into the fill pipe

That's where I would be looking, good luck!

 

[Rick10Tahoe]

When I replaced my canister, I vacuumed out the lines with a shop vac. I vacuumed a lot of charcoal beads out of the lines going to the gas tank. It was easy and very necessary part of the replacement

 

[iboughtatahoe23]

Alright y’all… so I can’t even get my gas to pump for a dollar. This is getting ridiculous!

 

[petethepug]

I know. I was ready to push mine out in the street and light it up when it was doing that.

Now that it’s fixed and I use the e85 non-emissions nozzle (without the snorkel around the nozzle) that dispenses crazy fast, I actually look forward to fuelling up.

It does get better after you’ve run the gauntlet of swapping out those parts and blowing the lines out. After that is just another 10-15 years of boring fill ups again.