No announcement yet.

fuel pressure regulator

  • Filter
  • Time
  • Show
Clear All
new posts

  • fuel pressure regulator

    hello all,

    i was testing the regulators on my 97 lsc with the fuel pressure gauge hooked up and noticed the smaller one is not regulating like it should. so i went to the parts store to find a replacement.

    however they cant seem to find the little one.

    from what i can see it looks like you remove a snap ring and then can take out the diaphragm inside.

    however im unable to find this part anywhere.

    is it a special order thing? or does it just have a wierd name thus making it hard to find?

    thanks all


  • #2
    You only have one fuel pressure regulator.

    Since none of my Mark VIII's are stock, I'm having a difficult time determining what part you are looking for. Do you have a pic?


    • #3
      Supposedly that one manages something with injector pulses, the regulator is held in with 2 bolts
      1998 Mark Viii LSC, Black but runny,138k Miles... Still
      The problems I have with this car aren't normal compared to the ones everyone else has


      • #4

        Thanks for the replies

        That's the culprit. I assumed it was another fpr And its part of the rail. When I pull the line the fuel pressure changes by 1 psi instead of almost ten on the main fpr when vacuum is pulled. Seems to have a stuck diaphragm lol


        • #5
          oops the pic didnt post lets try again

          Click image for larger version

Name:	fprithink.jpg
Views:	1
Size:	68.1 KB
ID:	473068

          that's the guy. i tried to pull vacuum on it and the flow only changed by 1 psi. seems to be stuck.. unless it's supposed to do that lol

          thanks for the wisdom fellas


          • #6
            for reference here's what i thought was the fpr

            taking vacuum away from this guy jumps the pressure to 40 so it looks to be good but the little guy on the other side of the rail doesnt seem to change when i take vacuum away or try to pull vacuum on it.


            • #7
              if that's not a regulator does anyone know what it is?


              • #8
                Fuel Pulse Damper

                Just make sure the diaphragm is not ruptured. That is why there is a vacuum line on the top side. If the diaphragm is ruptured you would see/smell fuel with the vacuum line disconnected. Since it is part of the fuel rail it is made serviceable by removing the snap ring.

                Seems odd to me you would note a pressure change with it disconnected? Did you plug the vacuum line when it was disconnected?


                • #9
                  Yes sir. Sure did. Pulse damper eh. Never heard of it lol what does it do? That explains why it didn't jump 10 psi when unhooked lol

                  Thanks again el presidente


                  • #10
                    It is akin to an accumulator... it simply dampens pressure pulses in the fuel line. The pressure pulses are presumably from the opening and closing of the fuel injectors. I'm not sure what impact a faulty one would have and I would need to look at the factory manual to see if there was any further information on it.


                    • #11
                      gotcha thanks again for the info driller

                      cheers all