fuel tank not releasing pressure correctly

[slim]

hey all, here's the situation, within the last few months I've been having issues with my fuel tank not wanting to "breathe" or release pressure like it should, it will only do it after it has been shut off for about 30 seconds, or i unscrew the cap, then i hear it tank "pop" back out and release pressure. at first i thought it was just the gas cap, but i replaced that and it still has the same problem. so I've been doing a little more digging and was then thinking it was just the tank vent tube, but then after doing a little more looking i saw on the rock auto website there is a vapor canister, filter, purge valve, and solenoid, and am now thinking it could be one of these thats not letting the pressure release when its supposed to. has anyone else had this problem or dealt with this before? any help is much appreciated. Thanks!

edit: it has also been hurting my mileage by 1.5-2 mpg

 

[BOTTLEDZ28]

My camaro used to do the same thing AND I didnt have the purge canister and all the other bullshit hooked up to it. It went away one day so I never looked into it. Just try un doing the line that goes to the purge canister and see if it stops the tank from popping. There shouldnt be any gas that comes out of that line. You will smell fuel vapor though

 

[slim]

well i did some more looking and messing around with it and opened the top of the canister and there was a bunch of crap in there, apparently theres bag(s) of charcoal in the canister and the bags broke, so the canister is filled with charcoal chunks that look like gravel. so i need a new canister and am going to blow out the plastic lines and also check the purge calve to make sure its working correctly.

and thanks for your input bottledz28! I am considering just doing away with the system, but think i will just fix it and be done with it.

 

[BOTTLEDZ28]

No problem. Dont bother wasting your time looking for another used canister from a junkyard because more then likely it will be in the same condition as yours. I would just get rid of it. If you smell a lot of fuel vapors and it bothers you then see if GM still sells new canisters.

And Im curious as to how to managed to open yours as all the ones I have had were sealed.

 

[slim]

well i didn't completely open it, there is a cap on the top of it i popped off, I'm gonna buy a new canister though