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Failed Emissions....help

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Impex, May 14, 2003.

  1. Impex

    Impex 1/2 ton status

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    here is the low down. failed last year took it to my mechanic, he hooked it up to his sniffer adjusted some things so it would pass, i went through for my 2nd time and passed came back to him and he adjusted back to run good.(i don't know much about carbs so thats why i paid) Now knowing that and not wanting to pay 60 bux this year here is what i did, i bumped the idle to about 800-900 ran the tank really low and added 2 bottles of rubbing alcohol and 91 gas to about half tank. passed loaded but failed the idle. did bumping the idle hurt me cause thats all i failed on?? its a 78 k10 edelbrock carb with true duals thanks guys!!

    here is the test results let me know if the scan is to hard to read and ill re scan it /forums/images/graemlins/thumb.gif

    [​IMG]
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

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    Did you get your cat good and hot before the test? Also, bumping the idle up usually helps pass the test. I don't remember the exact reason why, but it does.
     
  3. Impex

    Impex 1/2 ton status

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    hossbaby50: i don't have to worry about cats i dont have them /forums/images/graemlins/laugh.gif

    also wanted to add that i did a tune up not the long ago, so most of that should be good.
     
  4. Hossbaby50

    Hossbaby50 3/4 ton status

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    Where is your timing set? You might retard the timing some to help on the next test.
     
  5. 87sm465np208

    87sm465np208 1/2 ton status

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    my uncle did somthing to our 78' chevy K10 4x4 that made it pass, he adjust the carb some, probly leaned it out a bit and bumpped up the idle, then when the test is all done adjust it all back to where it was so you get your power back /forums/images/graemlins/smile.gif.
    also they say to run low octane gas, and might wanna try some emmission pass stuff like berrymans that they sell at autozone or carquest might sell somthin. good luck , i hope i dont have to deal with this on my 87.



    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/truck.gif
     
  6. GM Man

    GM Man 1/2 ton status

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    Lowest octane gas helps it pass, it burns easier.
     
  7. MOTORHEAD

    MOTORHEAD Registered Member

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    Check your timing as well. retard it a tad and see what happens. Have you ever replaced the cat? If not you might want to check into a new one (summit, around $100 for a Catco high flow). Is it a stock Q-jet carb you're running? I'm not sure if you can change the jets on smog-carbs but that might be something you might want to look into, knock it down a jet size if you can. I found a good tune-up, new plugs and reset the timing, change the oil really help me out. How many miles on the engine?
     
  8. MOTORHEAD

    MOTORHEAD Registered Member

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    Sorry just saw you stated you have a edelbrock carb. check out the jets your running in that thing and kick it down a size or two. This will lean it out for inspection and then change it back.
     

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