It could be something as simple as a twisted gas hose. I'm talking about the hose that runs from the external fill point to the tank. Mine was twisted, and after a slight turning to straighten it out, the problem was solved.
ETA: OOPS! Didn't read all of OP's post. Should probably replace filler neck assembly.
The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants.
Last edited by ValleyGunner; 09-10-2013 at 02:27 AM.