Can this be a Ing. Coil causing this, hard starting cold but once you get it started and warm it starts ok, I've been suffering a stalling problem also when cracking the throttle.

 

Do you have an engine light?
Do you have fuel and spark when it's cold?
A thought would be the CTS thinking it's extremely cold and flooding it.
Wouldn't hurt to check your timing.
I would also clean the IAC and check the TPS.

 

No codes no lights fuel psi ok don't think its flooding dont smell a lot of gas pulled plug not wet timing ok iac works well high idle cold and drops down ok cts could be the problem when idle finaly drops after iac radaitor fan kicks on but still have stalling prob. when cracking throttle idles fine