Can anyone tell me more about this part and how it works? Can't seem to find much of any info through search except part numbers? I've been having an issue of my car very hard to start when it's warm and was wondering if this could be it. I've replaced almost everything else (ignition coils, rotor buttons, ECU, ECT, fuel pump, etc.)

 

According to Alldatadiy.com (they call it Fuel Pressure Control Solenoid
);

"PURPOSE
The vacuum switching valve for fuel pressure control is used to raise fuel pressure during hot restart conditions.

OPERATION
During a hot restart, the engine control module energizes the vacuum switching valve which redirects the vacuum supply for the fuel pressure regulator to the atmosphere. When the vacuum is vented, the fuel pressure regulator raises fuel pressure accordingly."

For information on how to test it see attached pdf. For more information I would recommend that you start suscribing to Alldatadiy.com services.

 

running without that VSV didnt make any real difference to my car's hot starting, so i doubt its causing the problems you're having