Silly question but I just don't know how to do it. I have a '98 F150 with a 4.2l and 5 spd manual transmission. I want to test the fuel pressure but don't know how. Advice appreciated! Thanks!

 

Locate fuel injectors, on top of them is the fuel rail, somewhere on the fuel rail is a schraeder valve (threaded, like a tire valve stem). The fuel pressure tester is connected there. Turn key to on, pump runs for a few seconds, read pressure.

Two things to look for: 1, fuel pressure and 2, how long pressure is maintained after key is turned off?

Other info can be gathered with the gauge, for our level of diognosing, pressure and time period of holding pressure is valuable assistance.