The revs are higher (choke) when cold, hence why it doesn't stall. Soon as the choke is off, revs drop (too low by the sounds) and it stalls. These are EFI yeah? So there is no choke & idle adjust like on a carby.
I'd clean the
MAF sensor (can buy the cleaner at the local auto store), and check the vac lines to brake booster for a leak. Or the actual booster for a split in the diaphram.
My old 302 XE falcon did exactly the same, was the brake booster.