bad idle, valves, timing chain?

Engine, Transmission & Driveline

  1. Rusty Muffler

    Rusty Muffler Member

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    Hi,

    Just got my 66 Fury III 318 and runs fine except it's rough at idle. Vacuum is normal but shakes or flutters. Compression is good 180pounds per cylinder, just rebuilt the Stromberg 3-261 carb.

    Still idles rough. Can the compression still show good but the valves be too tight (I haven't checked the valves)?

    Also, could a loose timing chain cause this? Did they use a nylon sprocket
    on this engine?

    Engine has 125k miles on it.

    Thix!
     
  2. rapidtransitrick

    rapidtransitrick Active Member

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    no adjustable rockers there check all your vacuum lines put a timing light on it see if its steady
     
  3. Rusty Muffler

    Rusty Muffler Member

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    Thx Rapid,

    You may be mistaken about the rockers. I have a tuneup receipt that says they adjusted the valves.
     
  4. 7mag

    7mag Member

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    If you have had the carb off recently check for a bad seal/vacume leak at the base of the carb by spraying some carb cleaner or ether around the base gasket while the engine is running, if the idle picks up you may have a leak there, also check the idle jet screws for a blockage under them, take them out (count how many turns ittakes to remove them so you can put them back roughly where they were.) Blow out the jets with an air gun, put the adluster screws back in and re-adjust.
    Hope that helps
     
  5. rapidtransitrick

    rapidtransitrick Active Member

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    also check tour air bleeds run a paper clip through them to make sure they are open
     
  6. Rusty Muffler

    Rusty Muffler Member

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    Where are these air bleeds??
     
  7. MOBodyman

    MOBodyman New Member

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    I'm no mechanic but I think the '66 used the 'wide block' or 'poly' 318. Somewhere in the back of my mind I'm thinking they were indeed adjustable on this engine, but not on '67 and later.
    I don't have a Motor Manual here to check but maybe someone can make sure.
    Dallas
     
  8. Rusty Muffler

    Rusty Muffler Member

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    You are correct, this is a poly 318.
     
  9. rapidtransitrick

    rapidtransitrick Active Member

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    that explains the adjusable rockers i pm'd you about the air bleeds.if you need more imformation. you can google "carburetor air bleeds" there is plenty info there
     
  10. rapidtransitrick

    rapidtransitrick Active Member

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    that explains the adjustable rockers i pm'd you about the air bleeds. you can google "carburetor air bleeds" for more information many articles there on this subject
     
  11. Rusty Muffler

    Rusty Muffler Member

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    Thank you all for your responses!

    I took the carb apart again and rechecked everything and is ok. Idle is still poor so on to the valves!
     
  12. Rusty Muffler

    Rusty Muffler Member

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    Update: I adjusted the valves and found about 5 exhaust valves too tight. It idles great now!! Thx for all the responses.
     
  13. rapidtransitrick

    rapidtransitrick Active Member

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    there you go bet thats a load off