[David Hodgson]

Now I might be over thinking it but..... how much volume do the fuel rails hold and will this fuel, not being re-circulated, absorb too much heat and cause vapourising issues. Being under pressure might help in raising the boiling point whilst driving or high fuel usage situation, but if you've driven somewhere and parked in summer, when starting again there will be no fresh circulating fuel through the rails.
I suffered this on a carbied car, but then they run a lot lower pressure in the fuel line.