BlackWorksInc
New member
I doubt it has anything to do with ethanol blend... The 5th gen (and just about any modern car) is typically fine with it. It is more likely a loose connection somewhere or a simple matter of the fuel pump not acting 100% normal after sitting for a while.
Next time it happens.. (or just after it sits for a few days) Try to cycle the ignition on for a few seconds one or two times before attempting to start. This will give the pump enough time to bring up fuel pressure and purge the line. I think the system only allows for a short run cycle before cranking. If that does not build enough fuel pressure it may take one or two attempts.
There's a difference between vehicles being compatible with up to 15% ethanol (meaning concentrations up to 15% Ethanol will not eat up the fuel system and damage lines and gaskets) and them liking it. We've had PLENTY of Toyotas that ran some rather high ethanol blends and they just wouldn't run right; in those cases we had to drain the tanks and refill them. So I could see some higher Ethanol concentration or just bad gas causing issues, particularly if it sat for a while.
I'm not sure how regulated Ethanol is, I know with Bio-Diesel fuel quality varies greatly batch to batch in some cases and people were having issues with that.