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Thread: Engine loses power after launch

  1. #1
    Member MASTER JOURNEYMAN
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    Engine loses power after launch

    I'm running a Vega with a 750 h.p. small block with a 1090 Demon carb (96 jets). I use a trans brake, and come out at about 4500 rpm. When the car hooks well, and the front wheels come up, the motor will lose power instantaneously, then regain it....sometimes twice. I have a vent tube from breather to breather on the carb, and the float levels are where they should be. The car is going 9.50's @ 143, but I'm sure I could be in the very low 9's, if this problem goes away. There is really no loss of power or misfiring after the initial launch. Any suggestions?

  2. #2
    Senior Member RACING JUNKIE
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    sounds like you need jet extensions in the rear of the carb :wink:
    GOOD PARTS AREN'T CHEAP AND CHEAP PARTS ARE NEVER GOOD.........
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  3. #3
    Senior Member RACING JUNKIE
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    Quote Originally Posted by fast75vega
    sounds like you need jet extensions in the rear of the carb :wink:
    x2

  4. #4
    Member MASTER JOURNEYMAN
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    Already has them.....thanks anyway.

  5. #5
    Senior Member RACING JUNKIE fla1976's Avatar
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    Possibly a partially clogged fuel filter or weak fuel pump. What size fuel lines?

  6. #6
    Member MASTER JOURNEYMAN
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    Fuel lines are 10 AN......pump and filter are new...MagnaFuel pump w/ Aeromotive filter. I'm in the process of checking the fuel flow at the carb. That should tell me something. Also.....the regulator is new (Aeromotive). Fuel pressure gauge stays at 7.5 lbs.

  7. #7
    Senior Member RACING JUNKIE TheYellaBrick's Avatar
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    Might want to check your fuel pickup in the tank....
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  8. #8
    Senior Member RACING JUNKIE mopar1968's Avatar
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    Fuel isn't coming out of the air vent and going down into the engine is it :?:
    Head's up the true drag race!!

  9. #9

  10. #10
    Senior Member RACING JUNKIE
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    Quote Originally Posted by wrightway
    Are you running a power valve in the rear?
    that was gonna be my next question too ...... :wink:
    GOOD PARTS AREN'T CHEAP AND CHEAP PARTS ARE NEVER GOOD.........
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