Explain Gas Tank Pressurization To Me...?

[Fastime09]

The fuel vapors are released into the carbon canister by the pressure built up in the tank from fuel & vapors, then the pcm closes the tank pressure solenoid and then opens the canister purge valve and pulls the vapors into the intake along with outside air thought the canister, but thier is never a vacuum on the tank, only pressure, I'm not sure if you would have enough venting, some of the 5/8 hoses have a roll over valve in side & just to vent while filling tank, check the hose real good..

[r.barn]

Get a $10 vented fuel cap ....... problem solved

[LS1GMCTruck]

Get a $10 vented fuel cap ....... problem solved

Good idea. Yeah, I already removed ALL my EVAP equipment & programmed it out of the computer, years ago. No issues at all there. Just inquiring about fuel tank pressurization/venting...so buying a vented gas cap sure sounds like a simple fix, to a questionable situation. Thanks again guys.

[DBRODS]

I ran a 3/8 line off of the sending unit up to where the gas filler is and used a rear end breather on it...no problems here

[LS1GMCTruck]

I ran a 3/8 line off of the sending unit up to where the gas filler is and used a rear end breather on it...no problems here

Hmmmm...another good idea. Do they sell rear end breathers at the local auto parts store, or...? Thanks

[NITROUS]

LS1GMCTRuck, my fuel setup is just like yours with no issues here. I plugged at the canister, removed the evap solenoid and deleted out of the pcm. Your should be fine but a vented cap wouldn't hurt.

[LS1GMCTruck]

LS1GMCTRuck, my fuel setup is just like yours with no issues here. I plugged at the canister, removed the evap solenoid and deleted out of the pcm. Your should be fine but a vented cap wouldn't hurt.

O.K. Lance...Thank-you.

[GasGuzzler]

The fuel vapors are released into the carbon canister by the pressure built up in the tank from fuel & vapors, then the pcm closes the tank pressure solenoid and then opens the canister purge valve and pulls the vapors into the intake along with outside air thought the canister, but thier is never a vacuum on the tank, only pressure, I'm not sure if you would have enough venting, some of the 5/8 hoses have a roll over valve in side & just to vent while filling tank, check the hose real good..

Nope, the tank is subject to vacuum not pressure.

You need to vent the cap if all the EVAP has been killed.