98 Tahoe High Fuel Tank Pressure

[Stark98Tahoe]

1998 Tahoe LT - While off roading, I experienced what seemed to be very high fuel tank pressure such that fuel was pouring from the tank at the filler on uphills. Cap was on and tight to ratchet. Upon relieving pressure at the fuel cap, the engine would immediately die. Pressure would build again quickly when fuel cap was replaced. Engine would restart after a few minutes. Any idea what my problem might be?

 

[SunlitComet]

spam?

 

[retorq]

Never heard of tank pressure like that just tank vacuum ...

 

[Gzes]

Hmm never heard of it. Did you take a vid and post on YouTube?

 

[SunlitComet]

Helllloooooo spam anyone.

 

[retorq]

Why do you think it's spam my good sir??

 

[SunlitComet]

I have instinct.

 

[retorq]

Lol

 

[Stark98Tahoe]

No SPAM

Sorry guys, but this is NOT SPAM - Who could make this up?! Sorry, but I did not take a video. The first clue something was wrong was that I could hear the the pressure venting from the fuel filler cap when the vehicle was not uphill. Happened to get concerned at one point and got out to find fuel was pouring out around cap when the vehicle was headed uphill. Not much to see other than fuel going everywhere. There was clearly significant pressure under the cap as I slowly opened it to relieve it. Once the pressure was relieved, the engine would die and would not immediately restart. Bizarre. I did not experience the fuel leak on the way down the mountain, but could hear some of the pressure issue. Once back on the highway I had no further problem all the way home. Just know something is not right and need to get it fixed!

 

[retorq]

I've seriously never heard of pressure inside the tank ... that's dangerous. Good luck with it.