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Carb Tuning and Gas Mileage...

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 85blaze, Mar 7, 2001.

  1. 85blaze

    85blaze 1/2 ton status

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    How can get some better mileage by tuning up the carb? or any ways of better mileage? it has a 350 with holley 4bbl on it.. 700r4, 3.08, and 31" at's. It just kinda seems to lack powere and get bad mileage... no smoke.. once in a while it acts like it loads up and blows lots of black smoke when it idles to long. What can i do? Thanks

    ~Moshe

    Finally done after 8 months.. Not really.. IM never going to be done. Stroker motor is next
     
  2. Blazer_Boy

    Blazer_Boy 1/2 ton status

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    REBUILD TIME! I'd just save the headaches and have it done by a professional. It'll only run about $100 to get it done and you can at least cut that out of the equation for problems for some time. You could do it yourself but I would get some practice on some old junkers before I messed with the good stuff.

    Two lanes wide, twelve yards long, sixty-five tons of American pride....Canyanero!
     
  3. Thunder

    Thunder 3/4 ton status

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    Yep its rebuild time. It sounds like your power valve is bad. The power valve is located in the meetering body behind the float bowl. You can buy the power valve at most auto part stores. Be sure to replace it with the same number. Or to find the correct power valve for your engine. Hook up a vacume guage . Check vacume at idle. Divide reading on guage by 2. This is the number Hg power valve you need.
    That is the bad thing about holleys. One good backfire through the carb and the power valve is shot. you can buy a little check valve to stop this from happening. But the best thing to do to get better gas mileage out of a Holley is to toss whole carb and replace it with with a Quad jet.
     
  4. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Yep, toss that Holley and install a Quadra-Jet. It will perform a miracle if you swap carbs.
     
  5. pcorssmit

    pcorssmit 1/2 ton status

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    Damn, somebody beat me to it. Round-file the Holley, throw on a Quadrajunk or EFI it.

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     
  6. DMK

    DMK 1/2 ton status

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    I'd go with the quad too! I had a holley on a 69 corvette nothing but trouble,put q-jet back no troubles.
     
  7. CaptCrunch

    CaptCrunch 1/2 ton status

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    ditch the 3.08 gears... is way to hard to get going from a stop and then it lugs the motor most of the time anyways... getting so steeper gears should really help... 3.42's or 3.73's would be perfect

    1987 Chevy K5 Blazer- 350 TBI
     
  8. wayne

    wayne 3/4 ton status

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    Get a Quad......

    <A target="_blank" HREF=http://jamonline.homestead.com/fromthegroundupK54x4/89Jimmy.html>http://jamonline.homestead.com/fromthegroundupK54x4/89Jimmy.html</A>
    <font color=blue>Happy Trails[​IMG]</font color=blue>
    <font color=blue>Wayne</font color=blue>
     
  9. 85blaze

    85blaze 1/2 ton status

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    Where\'s a good place to get a quad?

    Should i get a new one from like edelbrock? or ??? Thanks!

    Finally done after 8 months.. Not really.. IM never going to be done. Stroker motor is next
     
  10. rocko

    rocko 1/2 ton status

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    Re: Where\'s a good place to get a quad?

    Get the Edelbrock Quadrajet replacement.. 4 wheel and off road just did a shootout w/ all the latest carbs.. the edelbrock's quadrajet beat them all hands down...


    Experience is something you don't get until just after you need it. <A target="_blank" HREF=http://www.rocko.coloradok5.com>http://www.rocko.coloradok5.com</A>
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: Where\'s a good place to get a quad?

    Anybody got a scanned copy or link to that article??

    Dorian
    My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>
     
  12. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Re: Where\'s a good place to get a quad?

    http://www.4wheeloffroad.com
    Click Truck Tech on left hand side
    Click Tech Articles
    Click Feature: The Ultimate Carb Shootout


    "I love the sound rice burners make when ya run over them"
     

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