Evaporation has a lot to do with the fuel quality. I buy the non ethanol premium at the same place for my old cars. I filled up before heading to MITP and turned around after I developed a bad surge. No issues until I filled up. Talked to a friend that buys his gas at the same place and he and half a dozen friends had experienced fuel issues the same time as I did. Sometimes mine will start up easily after setting and other times I have to crank on it a while. The only thing that changes is the fuel in the tank. We can't diagnose the OP's issue over the internet. We can only speculate what it may be from what we have experienced with our own cars. Kwik Star used to have 93 non ethanol. Now their 91 is crap. There is a privately owned Phillips 66 station nearby that has premium. I need to try theirs.