81 280zx NA

Car is acting weird on cold start. The first time I try to start it, it takes about 2 seconds of cranking then car starts then dies right away. The 2nd time I try it, it starts normal and idles fine. This consistently happens every time I start the car when cold. Before I did all the fixes below, car struggles to start and idle until it becomes warm. Now it only does it on first try. Any ideas or suggestions where I should check next?

These are the things I fixed/checked:
- new CHTS
- checked and cleaned cold start valve
- new air regulator
- no vacuum leaks
- checked afm
- tune up (air filter, fuel filter, spark plugs, oil change, pcv)
- new starter
- new ignition switch

 

If you figure this out, let me know. I have a 1990 Nissan Axxess that does the exact same thing. Falls on its face when first started, then its good.
My 280zx Turbo 2+2 did this when I first got it, but now that it has new gas, clean injectors, and a bunch of other fixes it is good. Although it did have this same problem when I got it out of mothballs this spring. Possible old fuel problem? Maybe throw a bunch of injector cleaner at it?
Normally I hate snake oil, but I only had to put in about 50 mL of power steering stop-leak to keep my floor dry, so sometimes it works!

 

Can you hear the pump going and system pressurizing with fuel first time you try to start it?

 

Did you check the electrical connector on the Idle control Valve?