Do you have a bleed circuit between your pump and
fuel pressure
regulator? Do you have heat shields on your fuel
lines? My guess is that
you may have experienced vapor lock. Without a
bleed circuit, the fuel
pump can't produce enough pressure to overcome the
fuel pressure
regulator
This should only
be an issue if the pump is not located at the lowest point in the line from
the tank. As long as there is liquid at the pump inlet – no
problem.
Al