Announcement

Collapse
No announcement yet.

Fuel pressure w/ vacuum referenced reg….

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Fuel pressure w/ vacuum referenced reg….

    So just installed the Pro Flo 4 on a SBC with an aeromotive fuel pressure regulator with the vacuum port to reference it to manifold vacuum. I hooked the vacuum hose up here and attached it to the small unused port on the base of the front of the pro flo throttle body.

    I have only gotten to drive it a few times but noticed that fuel pressure was still showing 43psi even though it shows 14 inches of manifold vacuum at idle. Regulator was set at 43psi fuel pressure with engine off and it was my understanding that the vacuum reference on the regulator would drop the fuel pressure the equivalent of vacuum so at idle it should only be 29 psi or so fuel pressure. Am I missing something or not understanding it correctly?

  • #2
    Same issue as here? https://forums.edelbrock.com/forum/p...sure-regulator

    Comment


    • #3
      Motor needs to be running fully warmed up and vacuum hose from regulator to manifold pressure plugged. Not the same with the motor running as motor off pump primed. Seems like it could be but the pump does not stay on if the engine is not running. I use my thumb to plug the vacuum hose. Once pressure is set, reconnect the vacuum hose. I sort of doubt it will go down to 29psi. Mid-30's maybe. Just try it like I say and see if there is any difference.
      Last edited by ElFuego; 11-25-2021, 08:48 AM.

      Comment


      • #4
        Are some of the smaller vacuum ports on the base of the Pro Flo 4 ported and not full manifold vacuum perhaps? I set the fuel pressure with engine off just using the 10 sec ignition on fuel pump prime feature.

        Comment


        • #5
          Throttle body has 5 ports. All full time vacuum.

          3/16" X 2.
          1/4" X 1.
          3/8" X 2.
          You do not have permission to view this gallery.
          This gallery has 1 photos.
          In my neighborhood, if you open your hood to check your oil, and the vehicle still runs after you close it.......Then your labeled the Neighborhood Mechanic.
          https://forums.edelbrock.com/filedat...?photoid=42773

          Comment


          • #6
            Originally posted by AllGoNoShow View Post
            I set the fuel pressure with engine off just using the 10 sec ignition on fuel pump prime feature.
            OK I would never do it that way myself. Not fast enough to accomplish the task. My system works the way it is supposed to work doing it the old fashioned way.

            Comment

            Working...
            X