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Won't idle at low rpms !! Ignition and carb issues?!! UPDATED !!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by ColAdo82K5, Nov 4, 2001.

  1. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Won\'t idle at low rpms !! Ignition and carb issues?!! UPDATED !!

    Please help !!
    My 82 k5 has an carb of unknown origin,I believe the carb is a 79. Anyway, the truck ran somewhat normal until 2 days ago. It now will just die at idle when in gear ! it's has been running a hair rich latley so i thought it would be the choke. Also, it won't high idle anymore when it is cold. I try to counter act this, i bumped up the idle speed but it will still die when in gear sometimes. I don't have a tach but i know this engine idling/ running way too high. It also is not a smooth idle, it will constantly try to die on me, but all that is needed is a a bit of gas and it will stay running. The carb linkages are in working order and i cleaned them. How do i set the high idle screw ? Why won't this thing idle well ?? by the way, This is an electric choke carb (did they have electric choke in 79 ?)and i tried Grim's ohm wiring technique and it came up like 99 or 100 ohms, instead of 70. But i'm not too good with my meter yet. so i don't know.
    Blake

    <P ID="edit"><FONT class="small">Edited by ColAdo82K5 on 11/07/01 06:50 PM.</FONT></P>
     
  2. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    One more thing, the choke will set when cold but seems to open up quickly. also i replaced the fuel filter.
    blake
     
  3. Burbinator

    Burbinator 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    Remember that ignition and fuel delivery problems have similar symptoms...have you checked the ignition components to verify that something there isn't the culprit?

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a>
     
  4. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    Hey,
    Would this be distributor related or actual ignition switches ? I havn't played with anything under the cap since owning the truck. New cap/coil/rotor is due ??
    blake
     
  5. Highlander

    Highlander 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    The two things that come to my mind is a vacuum leak or a bad plug wire. Have you tried a vacuum gauge yet? As for looking for a bad plug wire you could try this; You can do this two ways one is with a water bottle (a squirt bottle) Or a crayon and go to each exhaust and make a mark or squirt, If let's say 1cyl. is running ok it will melt the crayon fast or is you use the bottle the water will boil off fast. Now if you can get your hands on a infer red temp. gauge, (you point it at what you want a temp of ) All this stuff will help you pinpoint your prob. Hope this helps and good luck.

    Eric

    <a target="_blank" href=http://cethern.tripod.com/erics-home-page-and-other-stuff/>http://cethern.tripod.com/erics-home-page-and-other-stuff/</a>
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  6. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    I've got headers on, so your'e saying to put crayon directly on each tube to find one that is cold or not firing correctly ?
    blake
     
  7. Burbinator

    Burbinator 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    I would say that you should INSPECT your cap, rotor, coil, plug wires and plugs. Take a resistance reading on your plug wires; they should have low resistance and be fairly close to one another (the reading). The ignition switch shouldn't be a problem; if it cranks, it's good.
    I'm leaning towards ignition vs. vacuum leak due to the fact if you had a leak large enough to cause a no idle condition, you would definitely hear it and because the problem appeared suddenly. My former '82 Suburban had three decent vacuum leaks on it at one time and it still idled OK...rough, but OK...and it sounded like those deer whistles you put on your bumpers to scare the deer away!

    Keep us posted!

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a>
     
  8. Highlander

    Highlander 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    Yep the one or more that are cold are not firing right. I've used the spray bottle in the past, That worked for me and I've read somewhere about useing the crayon the someway.

    Eric

    <a target="_blank" href=http://cethern.tripod.com/erics-home-page-and-other-stuff/>http://cethern.tripod.com/erics-home-page-and-other-stuff/</a>
    AMSOIL Dealer # 529948
    Cethern@interfold.com
     
  9. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    Time for tune-up! Replace the cap, rotor, wires, plugs, and ALL vacuum hoses, and when that is all done recheck your timing. If it's been a while you are not going to hurt anything and all these items will be eliminated as possible causes. If it still exists, I would say you may have some crap in the carb or you have a bad cam lobe. Whatever the case, doing the above things will not hurt.

    See my rig at <a target="_blank" href=http://coloradok5.com/gallery/Leadfoot> click here </a>
     
  10. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    Thanks guys,
    I replaced my cap and rotor today, It fixed the problem for the most part. It won't die now but it will surge up and down a little bit when i'm coasting into the driveway and turning the wheel for instance but i still think my idle speed is higher than it was before. My wires are fresh still and I think it's time for new plugs. I've changed the PCV line. But my engine doesn't have many lines to begin with but i will cahnge them. WHAT DOES THE LITTLE PORT ON THE TOP SECTION OF THE CARB ON THE BACK DO ?? It's directly above the brake booster port about 2 inchs higher , on the top section of the carb, maybe a vent for the secondaries ? I'm going to try a rebuild of the carb this weekend. i squirt some carb cleaner down the carb every so often. thanks again.
    Blake
     
  11. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Re: Won\'t idle at low rpms !! fuel pump ?choke ? carb ? fast idle adjustment ?

    Hey,
    I changed my plugs today and it helped out a little bit. My idle is still too high though. I used to be able to lower my idle really low just to test it out(not to put in gear) So do you think a rebuild of the carb will help out or is it something else-it still surges and won't idle as low ??
    Blake
     

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