Vapor lock- additive?

RustyRatRod said

Are you 100% SURE your problem is vapor lock? You can use the old clothespin trick to diagnose it. That will tell you real quick.

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Not saying I’ve got vapor lock at all. I’m just reading the tea leaves here Rusty. I’m stuck in a loop on Boob tube that almost every car video that pops up lately is about vapor lock. The why and how but other than a mechanical fix- nobody is addressing how to fix by adding an additive, like the fuel companies did back when we were kids. 60’s and 70’s cars until
Charcoal canister emissions never had a return line. You vented thru the gas cap and did not deal with vapor lock. It’s only because of modern fuel do we deal with it. The quick burn stuff evaporates easily from what I am reading. How do we keep that from happening without a closed loop system. I’m not sure if I’m not dealing with it because I’m running 3/8” metal line to the big Carter fuel pump or my current additive or **** luck.