Vapor lock was an annoying problem for many car manufacturers...but solved the problem with a couple of design changes...
...moved the fuel pumps closer to the fuel tank, (and even inboard)...
...relocated intake delivery systems (fuel injection or carburetion) AWAY from the exhaust manifold.
But it sounds like your problem might be the fuel pressure regulator.
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car