Puffs of smoke

[JamRSW6]

Just discovered this site.  I am familar with Cliff as he rebuilt the quadrajet on my 69 GTO back in 2005.  This carb has always had a hard/long crank after shutting down hot.  Yesterday while working under the hood with the air cleaner off and right after I shut the engine off I see puffs of white smoke coming up through the primary side of the carb.  It seems as if gas was dripping and hitting something hot and causing it to vaporize causing the little puffs of smoke.  Ideas?  Thanks, 

[Shark Racer]

How is the idle? Super smooth, with responsive off-idle, or a little rough?

Do you have any nozzle drip? Nozzle drip will cause this as fuel puddles on the tops of the throttle blades and then vaporizes.

[JamRSW6]

It idles pretty good.  Not super smooth but decent.  Not sure about nozzle drip.  Is this when it is running?  I am assuming you look down the primary side of the carb to see if you are getting drops of fuel?  Cure for nozzle drip?  After it quit smoking I started it again.  It cranks several seconds and acts like it has gotten too much fuel.  I don't touch the throttle when trying to start warm.  My last quadrajet car would start instantly after it was warm. 

[Shark Racer]

Yes. Get it running at a warm idle and look down the primary barrels. You may want to use a mirror if your car is temperamental (backfire to the face isn't fun).

Nozzle drip's primary contributors are too much throttle angle or too little fuel from the idle mixture screws.

[Novarolla05]

Just something else to think about, your fuel may be boiling in you carb causing your engine to flood a bit after shutting it down. Are you using a phenolic spacer or some other kind of insulating base gasket? I didn't have any nozzle drip while the engine was running, but after I shut the engine down I could see some fuel coming out of the boosters. I swapped out a plain thin gasket for a spacer under the carb, and I haven't seen the problem since.