i know this isnt a chevy but ... i have and 85 f150 with an inline six 300 cui witha carb. for some reason whenever i fill up at a caseys gas station it wont start again for like 20 mins. i do the normal pushing the pedal down to elliviate the fumes and help start a flooded motor. i am confused here. the idle is set right and the mixture is to. any ideas? thanks