Popping out of carb

Discussion in 'Troubleshooting & Diagnosis' started by fbody_mike, Feb 6, 2014.

  1. captaincog

    captaincog New Member

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    I had this happen on my 71 many years ago before the new engine ( the numbers matching block is safely stored away) and after chasing timing, carb issues, ignition, wires, fuel, etc. to no avail....it ended up being the camshaft was bad. We stopped counting at 4 flattened cam lobes. I would look there first.
     
  2. 351maverick

    351maverick full time Ebay seller/hustler/car killer

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    time to bust out the propane torch
     
  3. Knuckle Dragger

    Knuckle Dragger Mayor of Simpleton Staff Member Lifetime Gold Member

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    You said you backed off the timing, did you reset it before you checked vacuum?

    High idle with a carb is not a vacuum leak unless it's pulling fuel with it. I'm not one to throw parts at stuff but you've checked fuel, compression and some of the ignition. With the weird ass failures I've seen I'd be putting a HEI module in it.
     
    Last edited: Feb 7, 2014
  4. fbody_mike

    fbody_mike Veteran Member

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    Well the popping was because of one or two bad plug wires. Like I mentioned above, I had replaced a few plug wires that were bad. Unfortunately the bad wires really fouled out the spark plugs too, so I replaced those all today and all things were running good except for the idle. Gonna get a whole new set of wires next.

    Idle was still really rough, but it runs fine throughout the power band. I also noticed that it would not stall with the idle screw all the way backed out and I could also remove the idle mixture screws completely and it would keep on idling. My father came around at this point and said he had an idea, he took a shop rag and covered the secondary side of the air horn and motor instantly died. So I pulled the AFB to see why the secondary butterflies were hanging open. I found that I slightly tweaked the primary/secondary linkage during the rebuild such that the primary was not forcing the secondaries closed. I tweaked the little arm, the secondaries sealed, and now it idles smooth again.

    So the whole time it was some bad plug wires, and ME, by introducing new variable with a "rebuilt" carb.
     

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