the mechanic at the shop said he set the fuel pressure to 7lbs my fuel pressure gauge is reading 3 - 3.5 at idle and temp. i didnt look when the car was still at the shop he just said it was set and i went home. more likely my gauge is bad or i need to reset the fuel pressure?

 

when should i set the fuel pressure with just the fuel pump on or at temp and idle?

 

either way it shouldn't change.