QuestionI cant put fuel in my 01 Jimmy last night I took the fill line apart to make sure there was nothing there I found what I thought was the fuel line vent (in front of the spare tire) about the size of a cigarette pack opened the top and found a sponge that was filthy cleaned that, now I still have the same problem. Do I need to replace that cigarette sized gadget?
AnswerHi
Here are the most common causes for your symptom
Check the valve stuck closed
Fill limiter vent valve stuck closed
Evaporative emissions (EVAP) canister restricted
EVAP vent valve stuck closed
Restricted vapor lines
High reid vapor pressure or high fuel temperature
Fuel filler hose is pinched or kinked
Ignition ON
The "cigarette" pack sized valve was the vent valve.
I would suspect this seeing how it was opened. It should be closed. It is a Normally opened valve that allows atmospheric pressure to equalize the fuel vapor system (EVAP) When it closes,and the purge solonoid opens it allows engine Vacuum to pull fuel vapors through the EVAP canister (Charcoal Canister). After a predetermined time the EVAP purge valve closes, along with the Vent valve being closed, the entire fuel tank is under vacuum. It then runs certian tests, checks for leaks, and after tests are run, it opens the vent valve and allows the system to equalize to atmospheric pressure.
I would reckon a guess that it it not opening and the system is staying under vacuum.
Is your Check Engine Light on?
If so get the vehicle scanned by a local mechanic you trust to see if you have an EVAP system code.
You may want to do this anyway, as the san tool they use should be able to look to see if the status of the vent valve as Open or closed.
Just advise from experience. Check with your local mechanic for further diagnosis as the fuel system can be tricky and dangerous to check.
Good Luck
Paul
