I wouldn't have believed it if I hadn't seen it, but a few years ago a buddy had a mid-90s GM car that was vapor locking during the hot months. However, if he ran non-alcohol gas (probably not available where you live), it would run fine. I suspect his fuel pump pressure was marginal, but I never went out of my way to screw on a pressure gauge to verify this.
A couple years earlier, I set up one of those large-scale water pumps that a local business had bought that was powered by a V-Twin Briggs & Stratton engine (prolly about a 16 horse or so) to drain a flooded clay pit. Of course, the carb sits right between the cylinder jugs and the fuel tank sits on top of the carb. At the time, the temps here were 100+ every day and the pump would run for about 15-20 minutes and stall. The owner couldn't figure out why it would quit and several calls to the tech help at B&S didn't help. Just on a guess, I unbolted the gas tank, moved the tank away from the engine and hooked up a fuel line that I unrolled from a spool. It happened to be about 30 feet and I simply had it on a gravity feed. The engine never quit after that until it would run out of gas.
Vapor lock can be a hard problem to fix and then it just sometimes goes away. (When the temps get cooler, lol)