im new to carb diagnostics (im a TPI guy) and my 84' Z has been doing this since i purchased it in Jan. id say about 75% of the time, when i start it in the morning (after its been sitting) it wont want to idle. itll stall unless i keep my foot on the gas. i have to keep my foot on it to maintain an idle for a minute or so before it will idle on its own. however, once in awhile, itll start up and idle smoothly with no problems. any idea whats causing this and how to fix? thanks

 

Mine does the same thing and if I choke it, it just floods and dies.

 

I have the same thing. I believe that if you adjust the ilde higher it will fix it. (the prob was really bad untill my dad got bored swapped carbs .... and adjusted it)

 

There is a small vacuum canister on the pass. side of the carb. If it is not functioning your engine will flood out immediately after startup. It should be fully extended with the enigine off. Immediately after startup manifold vacuum (via a short vacuum hose from the front of the carb) will cause it to fully retract and bump the choke open slightly. If it's not doing this, you should replace it (available from any good parts store). Not saying this is definitely the problem but it's a common trouble area.

The other thing to look at is the choke and the fast idle screw. The choke element should cause the choke plate to SNAP closed on a cool morning, engine overnight-cold as soon as you open the throttle slightly. If not, you've got binding in the choke linkage preventing this from happening. At the time the choke closes it also engages a "fast idle cam" underneath the choke linkage, that bumps up the idle speed any time the choke is on. The adjusting screw for this is directly underneath the choke linkage on the pass. side. You will see the screw head (usually phillips) pointing stright forward under there.