fuel pressure test method?

hello, my mechanic friend hooked a pressure gauge onto the incoming fuel
line,which he disconnected from the fuel rail, and then turned the key to
on, to see if there was pressure present. my Haynes book says to put an
adapter between the inlet hose and the fuel rail with a gauge attached to it
and then start the car to check the pressure. which way is correct or are
both methods ok?

 

First of all loose the Haynes manual, secondly, what kind of vehicle and
engine size is this??

Glenn Beasley
Chrysler Tech

 

both are acceptable and depends were the fuel pressure regulator is for what kind of
telltale test you are doing by disconnecting the fuel supply line and hooking up gauge