Fuel pressure help

Discussion in 'Fuel and Air Systems' started by Fisher, Aug 1, 2018.

  1. Fisher

    Fisher Old Guy with a Cool car.

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    I have a new Holley Blue pump and regulator which i installed today. Issue is 2 gauges installed , the one at the carb reads 1.5 lbs less than the one on the cowl? The cowl is 7.5 and the carb 6. Which is correct? Both are tapped at the same place.

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  2. Dana67Dart

    Dana67Dart Most undignified way to get to Colorado!

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    Neither! being a bit sarcastic but unless the gauges are calibrated they will only be close. eliminate the engine compartment one if you need to keep a watch while driving. will 1.5 psi make or brake your fuel system?
     
  3. brian6pac

    brian6pac Well-Known Member

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    Your autogauge is not at 0 it's way low so I would say that gauge is junk.
     
  4. pishta

    pishta I know I'm right....

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    There is a vent on top of the guage. The hotter it gets, the lower it reads unvented. you can unscrew the brass screw on top (?) to vent then return it but there were posts that said drill a .020 in the screw itself to permanently vent the guage. See if this fits your guages description. I know the rubber boot is the vent on top. venting should return you to zero.

    found this on Moparts. Note red test gauge and yellow unfilled against unvented liquid filled gauges over heat.
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    Last edited: Aug 1, 2018
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    • Fisher

      Fisher Old Guy with a Cool car.

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      Thank you for the replies. I am going to remove the Engine compartment one and leave the cowl one in play.
       
    • Dana67Dart

      Dana67Dart Most undignified way to get to Colorado!

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      good catch. How often we all miss the obvious.
       
    • pishta

      pishta I know I'm right....

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      its not junk, just needs its ears popped.
       
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      • brian6pac

        brian6pac Well-Known Member

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        Good call, never thought of that
         
      • Fisher

        Fisher Old Guy with a Cool car.

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        I took it off the car and plugged the hole, then popped the little rubber plug off it and the gauge sort of zeroed itself. I will leave it off.
         
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