L72 won't idle when warm. - NCRS Discussion Boards

L72 won't idle when warm.

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Mike R.
    Expired
    • October 25, 2016
    • 14

    L72 won't idle when warm.

    So, I just got my barn find L72 back (full engine rebuild with all original accessories rebuilt). The thing runs good when cold, but as it warms up, it won't idle, and is hard/impossible to restart when it dies. It even popped back through the carb (which was Rebuilt and Bench Tested by AEP). Thoughts? I was thinking possible vapor lock, but surprised it would happen while driving... After months of anticipation, I'm pretty disappointed it's not drivable...

    Thanks,

    Mike
  • Mike R.
    Expired
    • October 25, 2016
    • 14

    #2
    Re: L72 won't idle when warm.

    Should I dump the Original Carb for a modern one?

    Comment

    • Richard M.
      Super Moderator
      • August 31, 1988
      • 11323

      #3
      Re: L72 won't idle when warm.

      Mike, Many factors possible. Describe if stock ignition and carb, etc and exactly what engine specs it was rebuilt to. This will give others more data to help diagnose. A few thoughts....

      Is the choke fully open when it's hot? Maybe a vacuum leak when it gets hot?

      I'd put a vacuum gauge on it and note readings when cold then warming up and then normalized at temp. Did you adjust mixture screws using a vacuum gauge at early warm up for peak vac?

      If a high end shop did the carburetor rebuild did they test it?

      Rich

      Comment

      • Timothy B.
        Extremely Frequent Poster
        • April 30, 1983
        • 5186

        #4
        Re: L72 won't idle when warm.

        Mike,

        Try to determine if the hot idle condition is from being rich or lean. Take things one step at a time, make sure the engine tune is correct first (ignition, timing, etc.) then carburetor initial set up including emulsion screws.

        What you describe could be many things.

        Comment

        • David P.
          Frequent User
          • October 26, 2015
          • 49

          #5
          Re: L72 won't idle when warm.

          I have a '66 L72 and encountered exact same problem. What coil are you using and where did you get it?

          Comment

          Working...
          Searching...Please wait.
          An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

          Please push the back button and reload the previous window.'
          An unexpected error was returned: 'Your submission could not be processed because the token has expired.

          Please push the back button and reload the previous window.'
          An internal error has occurred and the module cannot be displayed.
          There are no results that meet this criteria.
          Search Result for "|||"