Joebrick

So my car idles fine when hot.
Starts great cold, fast idle then kicks down perfect.

But....if it sits for a couple hours it wont hold idle speed after restart. If I hold the idle speed with the gas pedal I just have to wait until it warms a bit and its good. If I don't RPM just drifts down and it stalls.

Doesn't smell rich, no smoke.

How would you go about a choke adjustment? Its mid-range that gives me fits.

73 L-82

Rescue Rogers

Next time its warm, pull the air cleaner and look inside the throat, see if you have fuel perculating past the rods. Just an idea. Also check and see if your choke is closing if you step on the throttle once before turning the key on. You can look up the choke adjustment for your specific carb. Its a simple adjustment, you might have it adjusted a hair to tight so its closing early in the heat cycle.

It could be your idle adjustment is off a bit or theres a vacuum leak, but non of these would go away after running a few minutes other than a rich mixture in the cylinders that needs to be burned off.

Could also be my eyes are brown because I'm full of something, but im just offering ideas to see if theres a direction for you to go in.

( editted) just reread your thread, is it hard to start when its hot? Spins but won't catch, you have to floor it while cranking then it starts ?
Good luck!!!

Joebrick

No, never hard to start when warm, fires right up...just wont keep idling. Drifts down in RPM unless I help it along....once fully hot I'm back in business.

I have heard it hiss, hiss, hiss (with air cleaner top off) after shutting it off as though drops of gas were hitting the manifold. Not sure how to prevent that one.

Rescue Rogers

What company carburetor is it? Your floats could need adjustment. I was hoping you would have trouble starting it too, because that would mean its flooding. Maybe the carb just needs a good cleaning. Could be crap in your idle circuit that isnt getting enough flow when its warm but expands enough so that fuel gets by when its hot.

That a tough one.

Joebrick

Yeah, I know...not an obvious solution.

It's the original Quadrajet just rebuilt last year with a Cliff Ruggles kit.. Runs awesome just does this little warm idle routine and it did it before the rebuild. The only thing I didn't do was seal up the wells, however they didn't leak when sitting with gas in the bowl on the workbench.

Rescue Rogers

If you know somebody with a spare carb, you could swap it out and see if it goes away. If it doesnt, then I would look at a problem different from the carb.