I'd check the fuel pressure regulator. To check it properly you'll need a fuel pressure gauge, But you could probably get a regulator from a junk yard for a couple bucks to swap out. I keep a spare regulator in my car tool box. Autozone or some other auto store might have a gauge to rent. If it's really shot some gas may leak out of the back of it when you pull the vacuum line off. If the pressure isn't high enough the injectors won't work right or at all. I think the cold start valve bypasses the regulator.
I don't know what the pressure spec is for your car, you'll have to look it up.

The other thing I'd examine is the air flap at the air flow meter. The one you pressed down on. They can tend to stick sometimes, especially after sitting. It should open extremely easily with no resistance at all.