Fuel tank pressure?

I have a 96 with 4.0 H.O. Sometimes while driving long distances the cab will get a strong fuel vapor smell then soon after it will spit and sputter then die. Everytime this happens I go and open my gas cap and a huge release of pressure comes out assgas:. If I wait a couple of minutes and the jeep will fire but after 50 or so miles the same thing happens again. The tank being full or empty, speed or operating temp seems to affect the issue. It did seem to happen alot more when I was pulling a boat. I checked for fuel leaks at the injectors and the tank but found nothing.

I would leave the gas cap loose and see if the same issue happened. If it does, then you know its not related to the tank pressure and it might just be a sensor issue (like the crank position sensor).

Gas tanks are vented and there shouldn't be an pressure.

It doesn't do it if the gas cap is loose but that would just confirm that the pressure is releasing from the filler neck not the vent system. Is there some kind of one way valve on the vent system that could fail. Also no codes are coming up when the problem happens.

Not sure bout a 96, but newer cars have a purge valve that vents the evap system which includes the fuel tank, when certain peremeters are met. But they usually throw an evap fault code.

There are vents on top of the tank to vacuum lines. Try to see if they are clogged or possibly a line capped off by a PO. I believe those lines go to the charcoal canister.