Hard starting when warm after engine rebuild

Just rebuilt the engine in my 02 gp gt. Have 300 miles on it plus about 5 hours idle time. First start of the day or when motors cold it starts fine. After i shut it off then try to restart itll crank for a few seconds start then immediately stall. I have to give it gas for a few seconds to keep it running but when its running it runs fine.. No pending engine codes. New plugs, wires. Fuel pressure is 55psi koeo, about 52psi running then jumps up to about 61 when vac line unplugged. Psi is about 58 when cranking.
Any one have any ideas

perhaps air metering and control? IAC, IAT, MAF, MAP, TPS, or O2 (long shot, addmitedly). If you're on Discord, ZZP has a pretty robust server going. Let me know if you want those instructions. Your issue doesn't ring a bell as to something we've faced here. My first thoughts went to a fueling problem, as well. Since you've ruled that out, I would go to breathing or spark. I'm going to assume you've already replaced the plugs and wires with your rebuild. Testing the MAF is pretty easy: with it running, you should be able to unplug it and it runs fine. When you unplug the MAF, it should start to stumble and roughen the idle.

Is there no moderator to delete these spam messages? (Obviously, NOT this post) ...

I'm a new owner of a 1999 Grand Prix, looking for some forums. Found a couple, plus this one. This one seems inundated with spam.

Yeah, sorry. The mods and admins all ditched the place a few years back. I'm really the only one left to keep an eye on things.

This forum is chock-full of lessons learned and suggestions. I can almost guarantee that what ever you wish to know about your new car, this place has it. Welcome to the might-as-well-be-dead site. I'm glad to see a new face around here.