without a datalog from cold start, it's going to be a bit more difficult to diagnose that problem. if you willing to buy a scanner, or an aldl cable for your laptop, i betcha you'll fix it really quickly..
if not, there are still some checks you can do. i'd start with the temp senders. if the ECM thinks its way warmer than it is, it'll be like you're starting without the choke on.
i'd start with the obvious. see what temperature it is outside, and check your intake air temp sensor, and the temp sensor on your waterpump via this chart. ignore the one on your drivers side head, it doesn't matter.
4th Gen LT1 F-body Tech Articles
only problem is, this doesn't really test the wiring to the ecm, but you can do that too, unplug the ecm, get a paperclip read this... make sure the value measured right at the sensor stays the same at the corresponding ecm pin
4th Gen LT1 F-body Tech Articles