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