When putting gas in the tank of our 2000 3.8 V6 car we have to do so VERY slowly or the gas pump will shut off as it would if you had a full tank of fuel. Do not know the history of this vehicle other than the previous owner did let us know about this issue before we purchased it a few months ago. I assumed it had a stuck closed/blocked vent valve as it has a P0446 DTC stored.
Removed the fuel tank today and started to do some tests. I was able to blow freely through the vent valve so I assume that the vent valve is okay. Then loosely sealed an air nozzle set at 5psi to the filler opening of the tank and slowly pulled the trigger. The tank started to expand and some air started to come out of the hose that goes to the vent valve from the charcoal canister. Next I disconnected the canister from the tank and did the same test. This time the tank only very slightly expanded and more air came out of the hose that was once connected to the canister than in the last test. I am assuming that I have a plugged up charcoal canister but also worried that there also may be a restriction or issue also in the (valve?) that is molded to the top of the tank as it does not quickly vent out the rather small amount of air that I am putting in. Or maybe that is normal result? Any thoughts or better ways of testing for this gas filling issue would be appreciated.
The canister feels very heavy to me and will expand and make noises when I barely put any amount of air to it by itself. I am thinking that the canister needs replaced. If that is the case, it makes me wonder about why it blocked up in the first place. Have not checked the purge solenoid operation yet...maybe there is no purge flow thru the canister? Could that cause it? Maybe something else? Again, any thoughts would be appreciated. Hopefully I am on the right track to solve this problem. Thanks in advance for any help!! Oh, BTW found the roll-over valve laying at the bottom of the tank....suspect the prev. owner decided to try and knock it thru the tank to try and fix this issue lol! I don't blame him for trying...the tanks don't come out of these too easily.