DoctorDex did you ever try this??
The removal not replacement.
Stealth 316 - Fuel Pressure Regulator Upgrade
Stealth316.com by:Jeff Lucius
"The fuel pressure control solenoid (or valve) is used by the engine control unit (ECU) only to increase fuel pressure during hot engine starts when there is a greater possibility of fuel vapor being generated in the fuel lines. When the air intake temperature exceeds 140ºF (60ºC) and the engine coolant temperature exceeds 194ºF (90ºC), the ECU uses the fuel pressure control solenoid (for up to two minutes) to allow outside air into the vacuum hoses to increase fuel pressure. In addition, the ECU increases fuel injector activation duration (richens the mixture).
These two actions by the ECU are what I believe is a cause of the hot-engine hard-start condition I and many others have experienced on a hot summer day after turning the engine off for a short while. The engine acts like it is flooded for maybe a minute then runs fine. Because this is the only purpose of the fuel pressure control solenoid, I decided to remove it. I don't think there is much we can do about this part of the ECU programming short of going to stand-alone engine management.
Owners that have removed the fuel pressure control solenoid, whether upgrading to an aftermarket FPR or not, have not reported problems related to this. I will update this web page if I encounter problems."
Did you ever try this?? I have the same sort of problem. I have been waiting to try it, but my car has been at the shop for the last 7 weeks.