[mr48chev]

Yes, I would be inclined to think that the gas that we have today would go bad if it sat that long. Unless you use a gas stabilizer in it there is a fair chance that it will go bad if left for more than a couple of months.

Also unless I don't have a choice I only buy gas from newer name brand stations or Costco or Safeway. I don't go to old stations nor do I go to off brand or no brand stations.
My brother-in-law drives a fuel truck in the Seattle area and
delivers to all kinds of stations. He says that Costco will not let drivers "stick" the tank because they don't want potential contaminants in the tanks.

Enough of that but as I said before if nothing changed I would suspect fuel that was contaminated or had gone bad from sitting.
If it has rained a lot or the humidity is high you might have condensation inside the cap. I've had to deal with that more than once with customer rigs in the past.