Car is a 91 GTA 305 TPI with a automatic.

The issue I am having is that if the coolant temp is say in between like 110 and 160 it will take a long time to start and dump fuel (I think) and I will get a huge ploom of smoke. If its cooler or hotter then that it will start as soon as you hit the key. I also get a little puff it cold start. Here is what I have gone through

CTS is brand new
Injectors have been replaced recently by the PO but they are multecs and I don't know where they come from
Spark Plugs are new from when I did the headers (old ones had no fouling what so ever)
O2 sensor is brand new
New Cat Converter
TPS checks out good
IAC appears to be working as it should
All Ignition components are new, Plugs, Wires, Cap, Rotor, and ICM
Fuel Pump was replaced recently with a AC Delco unit and the presure is perfect.

It had this condition before and after the header back exhaust install

I suspected the "new" multec style injectors of being leaky but...

now the odd part is that if it sits outside in the sun and its super hot like yesterday it was 96 at my house and it was humid as hell. I turn the ignition on and the temp gauge is already over 100 and it gave me a long crank and a big ploom after sitting 3 days

If anyone has any ideas of where to point me I would appreciate it