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tuning edelbrock carb for emissions?HELP!!??

Discussion in 'The Garage' started by moturbopar, Jul 23, 2005.

  1. moturbopar

    moturbopar 1/2 ton status

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    Location:
    mesa az
    hi all I took my 79 blazer through emissons today, it did well except on HCs on the loaded reading. Here is how it did.
    idle HCs 110 max of 220
    , COs 1.55 max of 2.00
    loaded reading
    was 281 max of 220
    COs 1.35 max of 1.50

    I tried retarding the timing a little but it really messed with the idle readings.
    Anyways I was wondering if I should step down 2 jet sizes to reduce the HCs on loaded? The carb is a 1406 edelbrock performer. The jets sizes and needles are .97 jet with the .75x.47 rods.
    I was going to change rods but they dont make any that are leaner. I have a set of .92 or .95 jets. Which should I try? I only have one retest and dont want to spend another $19 on another test. do you guys hink jets will help the HCs ?
    Thanks
    Shawn
     
  2. puckhead

    puckhead 1/2 ton status

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    Location:
    colorado
    what is your altitude there?

    i can tell you what i put into mine for my altitude approx 5280'

    you may need plugs or wires high hc usually indicate a cylinder not fireing
     
  3. down4thakrown

    down4thakrown 1/2 ton status Premium Member GMOTM Winner

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    try putting a cap full of acedtone in youre tank and a tune up if you haven't already.
     
  4. rumbly truck

    rumbly truck 1/2 ton status

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    which powervalve spring are you running. i think a 1406 comes with the yellow one about 4" hg you might try a couple of jet sizes down and a stiffer spring to try to keep more fuel out of the primary circuit until you need it
     
    Last edited: Jul 23, 2005

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