Fuel pressure gauge

Discussion in 'Forced Induction Mopar' started by BoostedLilRe, Jul 19, 2018.

  1. BoostedLilRe

    BoostedLilRe Well-Known Member

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    So i have two gauges. I have a small mechanical pressure gauge on the the regulator in the engine bay. I also have an electric autometer pressure gauge in the cab. Cab reads 8.5 psi and the one on the regulator says 6.5 psi. Here is why i m asking. I have been fighting a rich idle and i set the fuel pressure by the gauge on the regulator but i'm thinking its not right and i am over pressurizing the carb causing the rich idle because the electric gauge is saying 8.5 which i am now thinking is correct. Any thoughts?
     
  2. lenky1

    lenky1 Well-Known Member

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    Electric fuel pump or mechanical?
     
  3. BoostedLilRe

    BoostedLilRe Well-Known Member

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    Electrical A1000
     
  4. lenky1

    lenky1 Well-Known Member

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    I had the same issues. Electric pump running rich. On start up my gauge would show 8 and after running a few minutes it would drop to 5.5. Which is where i had it set. I ended up changing fuel pumps as mine was the culprit as it was surging
     
  5. BoostedLilRe

    BoostedLilRe Well-Known Member

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    I’m leaning towards the cheap mechanical gauge being wrong because the needle isn’t steady. The electric is Rock solid. I’m going to adjust pressure by the electric gauge this afternoon and see what that does. Fuel pump is in the fuel cell and pretty new not to say they can’t go bad quickly. 8an feeds and returns.
     
  6. dusted

    dusted Well-Known Member

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    My vote is for the electric, use it as your reference. Also check to see if the throttle blades are open too much. I had this problem and had a rich idle.
     
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    • BoostedLilRe

      BoostedLilRe Well-Known Member

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      Reset fuel pressure by electric gauge. Rechecked the float levels then turned the mixture screws all the way in. Turned each one out 1.5 turns started truck and afr high 11’s turn the screws in a quarter turn and idle screw out a full turn now afr 12.8-13.2 @ 800rpm idle. Leaving it alone now and gonna put some miles on it and see how it responds.
       
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      • Walker434

        Walker434 Well-Known Member

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        When I had a cheap mechanical gauge under hood it never read correctly because of the heat.