I have a 87 Z and the fuel pressure is
set at 48# with the vaccum off and its
about 42# pounds with the vaccum on.When
the car is first started the pressure is
fine but after a while when the car warms
up it falls about 4# of pressure.I have a
new guage and pump installed and the same thing.Does everyones TPI do this or do I
have a problem.The only thing I have not
changed is the regulator.Has anyone had this
problem let me know.

 

Normal fuel pressure at Idle I was told is
37+/- 3psi.

 

Yes I know what normal pressure is
but should it lose pressure when it
runs for a while?I run that pressure
because it runs best there.