gas tank over pressure

Awhile back I went to north Georgia for a week end camping/trail riding trip in my 95 xj. the average temp was about 100F during the day. after a 4 hr hi way drive we stopped for gas and when i went to take the cap off it began to vent, a lot. about 5 min later i could take the cap off and begin to fill slowly since the pump kept cutting off as though the tank was full.

Half-way to the camp site we stopped for a view and had a repeat of the venting experience. the next day it was fine all day and has not happened since.

I was running HOThttp://www.naxja.org/forum/images/smilies/flame.gif, abt 230 on the engine and transmission peaked at 250. I also melted the carpet under the rear seat on the passenger side.

any ideas? even though i was running hot the tank should vent to prevent over pressure.

Couple of things involved.

The EVAP system is supposed to take fuel vapors and let the engine burn them. The fuel cap is supposed to allow air in to replace the fuel that has been pumped out and the vapors that have been taken. Also, the fuel cap is supposed to vent extreme pressure to the atmosphere--note the extreme. Try replacing the fuel cap, make sure you get a quality cap of the right application, and inspect your EVAP system.

Good luck.