hello, my mechanic friendhooked a pressure gauge onto the incoming fuelline,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?[/align]

 

If you "dead head it" to the gauge, like your mechanic friend likes to do, you can't test for leak down at the injectors. The fuel system should pressurize and hold the pressure when you turn your key off. If not, something is leaking, "sticking, gummed up injectors, or bad check valve etc. You are correct your mechanic friend is WRONG.