Hey guys. I've got a mechanical quadrajet rebuilt by Holley. The thing works great except I have trouble pinning down the idle speed. If the engine is cold the idle speed is down around 400 rpm and stalling. As the engine warms, the idle comes up to 800 or 900. It only takes a few minutes.

After driving if I stop at a light the idle will be at 800 or 900 rpm, then if its a really really long light it will slowly sink down to 600 rpm.

By the way, I have really easy warm starts but I have to pump the gas once to get a good cold start.

Any thoughts?

 

Sounds like it's not setting the fast idle cam when cold.

Not sure

Normal for a carbed engine. This one pump is what should be setting the choke/fast idle when it's cold.

 

Thanks for the tips!