I have a '77 CJ 5. Same issue, EVER SINCE I'VE HAD IT!
On my CJ the fill hose goes in maybe 3 inches, then it makes a 90 degree turn to the left and then almost immediately, almost a 90, downward toward the tank.
I thought maybe, being as old as my Jeep was, that possibly the Fuel Tank Vent was the issue. On a CJ there are 2 items on the way toward the end of the tank vent system (ending at the charcoal canister), one is a "Roll-Over Check Valve", the other is a "Liquid Check Valve".
I thought maybe one of these 2 items might be old/ messed up/ plugging off the vent, 1st I took it loose and s. Ucked and blew thru it, all seemed GOOD AND CLEAR! So I took it one step further.
I temporarily vented the tank into open air, at the tanks connection to the OEM vent. I tied it high up on the back of my Jeep, and went to the service station pump. ABSOLUTELY NO CHANGE, STILL HARD TO GET IT TO TAKE FUEL WITHOUT OVERFLOWING AND CUTTING OFF REPEATEDLY!
This has been my LIFESAVER, for many years now:
IF I TURN THE PUMP HANDLE UPSIDE DOWN (DRAPING THE PUMP'S HOSE OVER MY SPARE TIRE, AS TO NOT HAVE TO HOLD IT UP)
UPSIDE DOWN WORKS WELL. YOU JUST HAVE TO BE READY TO LET GO OF THE HANDLE QUICKLY, IT WILL NOT SHUT OFF ON IT'S OWN, WHEN IT GETS FULL!
I CAN USUALLY HEAR IT AS IT NEARS THE TOP (IF THERE IS NOT A LOT OF TRAFFIC NOISE, SORTA SOUNDS LIKE A GLASS GETTING FULL.)
THE ONLY WAY, I HAVE SEEN TO FIX THE ISSUE FOR GOOD, IS TO CUT A NEW FILL INTO THE PASSENGER SIDE OF MY JEEP, ELIMINATE THE BENDS, THUS A STRAIGHT SHOT INTO THE TANK, AND DO AWAY WITH THE "REAR FILL".I REALLY DO NOT WANT TO MODIFY MY JEEP LIKE THAT, SO I WILL CONTINUE THE UPSIDE DOWN THING, WITH THE SPOUT.
LET ME KNOW IF THAT HELPS AT AT!
Thursday, May 5th, 2011 AT 3:17 AM