Fuel pressure questions
I was testing the fuel pressure on my 1993 Taurus 3.0L. I put the tester on the pressure relief port (an Actron III tester). Started the car and got around 31 psi. My repair manual says it should be 39 psi. Then I tried something....I unplugged the vacuum line from the pressure regulator and the pressure shot up to 40 psi. That kind of sounds backwards to me. If I look at a cutaway of the regulator, if a vacuum pulls on it, the regulator should open more and allow more fuel. Am I missing something here? Is the regulator bad?