Quote:
Originally Posted by Mattsvtcobra
When I took off the air cleaner, I noticed that the butterfly was open. The car has not been started for about a week. When I started your procedure, it closed and was up just a touch. Should the butterfly be open like that when the car is turned off?
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Yes, that's the way an automatic choke operates. It will be fully open from when it was last run - the heating element in the choke pulls it open. After it's shut off the bimetallic coil cools and applies spring tension to the choke mechanism. The first touch of throttle will release the spring tension and pull the choke plate closed tight. Once it's started engine vacuum operating on the choke pull-off mechanism will pull the choke open to the set point. After that the bimetallic coil will continue heating while the ignition is on, allowing the choke plate to open further and further until fully open. There's also an interaction with the fast idle cam to keep the idle speed higher until the engine is warmed up.
More here:
https://forums.holley.com/entry.php?...rel-Carburetor
This article has good instructions on adjusting carbs. It shows a pull-off adjustment you won't find on Holley's official pages - it's the adjustment I used on mine to make it run properly.
https://www.chevelles.com/threads/ad...#post-11389045