1986 Nissan 720 stalls - Please help

[MichaelWR]

Hi everyone! I am new to this site but it is great to see all of this information for the Nissan trucks and stuff that we love.
I have a 1986 Nissan 720 truck w/Z24 engine with 110,000 miles. Has always run great.
A couple of months ago I noticed that when I start the engine and put it in first gear the engine will stutter and stall. This will happen a few times. However once it is warmed up no stalling and it will run like a champ.
I have checked all of the following:
New spark plugs properly gapped and NGK wires
Replaced original alternator and battery
Checked both coils - no issues
Replaced and checked all vacuum lines - thank you Nico board member for the detailed instructions - absolutely terrific information
Tested the EGR - moves up and down no issue ( although my 1986 Nissan Service Manual states that the valve should remain open for 30 seconds once vacuum is removed - mine does not remove the vacuum it closes )
Replaced the oxygen sensor
Replaced the canister fuel filter ( not the filter inside the electronic fuel pump -does anyone do this?)
The truck runs noticeably better BUT I still get the stall. I have the impression that perhaps it is something in the carburetor - the gasoline level in the carb is at the site level where it should be.
Any and all help would be much appreciated and many thanks in advance.
Regards
Michael

[Rev_D21]

The automatic choke could be the culprit in this situation. If it's stuck open the truck could be running a bit lean when cold.

[MichaelWR]

Thanks Reverend. I appreciate the feedback. Dumb question? How do I troubleshoot examine the auto choke - I imagine that it is part of the carb?
Thanks Reverend and have a great Memorial Day weekend!!

[PEZi]

Pull the top of the air filter housing off, and look down the carb. The passenger side barrel should have the little flap closed when cold, and open when warm. That flap is your choke. Happy hunting!