350 sbc runs rough and blows smoke

Discussion in 'Engine Topic' started by Justin Berke, Jan 16, 2019.

  1. Justin Berke

    Justin Berke New Member

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    So I still have this problem with my Camaro, it won't idle and whenever I start it the throttle is almost floored and it will blow lots of smoke I assume it's the carburetor. It runs extremely rough and backfires when it is above 1400 rpm and it will die if I give it not enough throttle. My carb is a hr650 cfm quickfuel, and I have a mallory high volume fuel pump with a regulator. I just did the spark plugs and it's not the timing. I think it's the a/f mixture, I adjusted the 4 corner idle screws to factory settings aswell.

    Any ideas?
    Thanks,

    Thanks,
     
  2. cadillac_al

    cadillac_al Veteran Member

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    I can't help with the carb but I would triple check the firing order.
     
  3. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    What color smoke?

    Im assuming black and also wonder about timing issues.
     
  4. Justin Berke

    Justin Berke New Member

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    Yea its black
     
  5. Justin Berke

    Justin Berke New Member

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    Well actually more blue than black
     
  6. Bandit723

    Bandit723 Veteran Member

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    Floats adjusted correctly? How many turns do you have the idle mixture screws turned out?
     
  7. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    Blue tends to indicate burning oil. What I'm hearing is that the car runs badly, pretty much all of the time.
    Until we have an impression on timing everything else is kind of moot.
    Initial timing can be baselined at ~ 4deg BTDC at idle advancing to ~30 deg at 2500RPM
     
  8. Justin Berke

    Justin Berke New Member

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    Well I was actually thinking maybe the floats are stuck, I may have to disassemble the carb. Have the idle mixture screws out factory settings 1.5 turns out.
     
  9. Justin Berke

    Justin Berke New Member

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    Okay
     
  10. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    First thing I would look at - stuck float, front or rear. As soon as you shut it off, put a rag under the carburetor and take the sight screws out. If gas runs out, you've found it.
     

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