Thoughts? Strange Sound From Gas Tank.....

Took the CJ5 (F-head) out for a ride today. After driving for 30 minutes (last 5 up a mountain), I turned it off and noticed a gurgling sound coming from the gas tank. Sounded like bubbles. Looked under Jeep and in floor and there is no gas leaking. Checked under the hood and there were no leaks around the fuel pump or carb. It did stall a couple times on the short ride home, started back instantly but I needed to pump the gas to keep it going......

As a bit of additional info, after it has set unused for several weeks it takes a while to start. Feels like it has to pump gas up from the tank. Has a fairly new fuel pump as the old glass bowl unit started leaking a couple years ago.

Thoughts

 

sounds like pressure is building up..is the gas cap venting? not familiar with how your fuel system vents

 

Mine return line goes in the top of my tank. If I park on a hill and shut it off I hear the gas run back into the tank from the draining return line. But I wouldn't call it gurgling so I guess that's useless info to you. Sorry that's all I got

 

I have had gas in the under seat tank start to boil. It was a fairly constant issue when I was in the desert last summer. I never did come up with a solution other than stopping and waiting for it to cool.

 

Not a pressure issue, the cap doesn't seal that well. Boiling would sound like what I heard. Does NOT sound like a good thing.....

Going to check routing of fuel line next chance I get. I do remember it runs near the exhaust in stock config which seemed strange to me. Also may look at adding some floorboard insulation under the tank. It has the stock strips under it but they may have moved. Just don't want anything that will hold water.

 

Could also result in "vapor lock" which is why it was stalling.

 

This.

(And no return line on F-head.)

 

Please start running!