I have mazda astina of 1991 (323F BG).



I checked the Fuel Pressure Regulator with and without the Vacuum Hose From Solenoid Valve, and the result:
1. With Vacuum Hose Attach, there is a high pressure fuel to the return line tank.
2. Without Vacuum Hose Attach, there is still fuel that goes to the tank through return line pipe, but the pressure is lower than point 1.


And I think without the vacuum attach, the car acceleration is more responsive and the engine is just running fine
.
No I Unplugged the Vacuum hose to the FPR, what is worst scenario could be?

 

Here is a link to some info on the FPR, how it works etc.
http://www.240sx.org/faq/articles/fu...gulator_wo.htm

 

still i wonder why my car is running just fine (if not better) without FPR,
this mean that FPR is broken?