Have you guys ever seen a fuel pressure regulator read low? I was checking out a 92 Ford truck & it only had 15psi w/ vacuum, 28 w/out. Spec is 35/45 psi. The regulator was not leaking through the vacuum hose, it would hold pressure too, so I dead headed the fuel pump & got 90psi quickly. I've just never seen one do that, some of the newer cars vary the voltage to the pump , so it would vary the psi.