VX trouble

[VehiGAZ]

Generally speaking, regional regulations dictate the types and concentrations of oxygen-enhancing additives like ethanol or MBTE, so it's probably not a "Costco gas" or "76 gas" thing. Check the pumps at several different gas stations to see what they have in them and how much - they will probably all be the same.

We used to have MTBE in our gas in CT, but they started finding traces of it everywhere in the environment, so they got rid of that junk and mandated adding ethanol up to 10%.

steelzeus is thinking that you're running pure ethanol, I think, not gas with ethanol as an additive

[Ironman pilot]

I talked to a Costco rep. He stated that the gas that they supply has about 10% to 15% ethenal. I travel to LAX on my commute to work and when I use Cheveron vs. Costco, I can definitely see a difference... The Cheveron gives me more miles.

P.S. Over a week and still running fine, no stalls. Cleaning the Idle control valve is the fix for this idle problem