Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

holley carb...what the f^&%

Discussion in 'The Garage' started by the fall guy, Jul 18, 2004.

  1. the fall guy

    the fall guy Registered Member

    Joined:
    Jul 1, 2004
    Posts:
    35
    Likes Received:
    0
    I installed a holley 670 street avenger on my 85 blazer 305ci. The only problem is that now i have to wait a good 5 to 10 min before i can even drive the thing because it keeps stalling out or back firing. My choke is fine and so is my idle mixture and vacuum lines. Can it be the carb is too big or the air pump(it is still connected) /forums/images/graemlins/angryfire.gif /forums/images/graemlins/k5.gif
    p.s. The engine is stock as well as the exhaust.
     
  2. Twiz

    Twiz 1/2 ton status

    Joined:
    Mar 8, 2001
    Posts:
    3,729
    Likes Received:
    0
    Location:
    Clearfield Ut.
    [ QUOTE ]
    The only problem is that now i have to wait a good 5 to 10 min before i can even drive the thing because it keeps stalling out or back firing.

    [/ QUOTE ]

    In the middle of summer? I'd take a closer look at the choke, just to be sure.
    Otherwise;
    Backfireing through the carb or the exhaust? Though the carb - it's lean. Through the exhaust - it's rich. (rule of thumb)
    If it's poping through the carb, when does it happen? Off-idle? Tip in throttle? Wide open? Knowing the throttle position, will help zero in on what circut to look at.
    If it's Backfireing through the exhaust, are you sure the choke is pulling off correctly?


    It's difficult to diag one over the net - ya-know. Every lil bit of info can help. Otherwise, you just get "hip-shots".
     
  3. mrk5

    mrk5 The Sticker Guy Moderator Vendor GMOTM Winner Author

    Joined:
    Apr 20, 2004
    Posts:
    12,327
    Likes Received:
    1,031
    Location:
    Northern Colorado
    Did you change plug wires? I've had something similar happen from getting plug wires on wrong.

    Don't know if that will help or not, but I thought I would throw it out there.

    The only other things I can think of, besides those previously mentioned, is to make sure carb is securely bolted on.
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,059
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    A backfire through the carb can blow a power valve and make it run rich.
     
  5. backcountry

    backcountry 1/2 ton status

    Joined:
    May 27, 2004
    Posts:
    916
    Likes Received:
    0
    Carb is a little to big for that motor unless it has alot of mods and is set up for high rpm's

    Alot of people over carb their engines.
    The speed at witch air enters the carb is very important. The larger the openings the lower the speed.

    Simular to exhaust systems. Usually the quicker the exhaust exits, the better.

    Here are a few links for you to check out.
    http://www.chevyhiperformance.com/techarticles/148_0403_choose/

    http://www.classictruckshop.com/garage/shopmathcfm1.asp

    /forums/images/graemlins/peace.gif
     

Share This Page