454 Idle

I have a 454, with a rough comp cam, and a holley 750. I had the carb rebuilt and it was running and idling great. Seems since the timing was reset if the engine is cold it will not idle after a minute of running. Then I'll set the idle up to stop the stalling but once hot is runs too high and I turn it down and the cycle starts over again? It is not the linkage as I just replaced it all and disconnected and I have the same results. Idea??

have you checked the fuel pressure

Sounds like a choke adjustment. When the engine is cold, there is a cam connected to a bi-metallic spring which produces a higher idle. Once warm, the spring relaxes and the cam rotates allowing normal idle.

If your carb looks like this, try setting choke to middle index marks and work from there in 1 mark increments.

Good Luck,
Glenn