Hard HOT starting

worked for my Duster.

Except that on really hot days, I can shut the pump off and keep driving forever, and it just keeps siphoning fuel :/

I assume that you are kidding about siphoning,cuz I can't see how that would be possible.Liquids, under gravity, just don't flow uphill. And float valves are suction breakers.
But I'm willing to learn.......