Hi, I've been having a very tough time filling gas into my 1992 940 sedan. I Must fill it very slowly or it shoots gas back out the filler neck at me. I figure it has a clogged vent somewhere, but where to start. I've also read it could be clogged up at the carbon canister. Should I blow compressed air back thru the canister line? How does Volvo vent the tank? I've heard something about a roll over valve too.. Can this be eliminated if it's the culprit? Any advice would be great,

Thanks!
M.