88 Iroc Z, 305 TBI, totally stock -

Last week this engine began stalling right after starting up until it got "warmed up." I need to start it maybe 20 times (with it stalling maybe a second after firing right up) until it runs right. Once it decides to keep running, it runs and accelerates fine - No problems whatsoever until I shut it off for a couple of hours or over night.

Fuel pressure is holding a very steady 12-12.5 psi once it starts running right and the output from the fuel pump relay is a steady battery voltage, so I believe the relay and fuel pump are fine. And the injectors spray a nice cone-shaped pattern, when it is running. But for some reason, the fuel shuts off after a second or so when it is "cold." (Note that "cold" is a fresh start in 50 to 80° temperatures!)

I have hooked up a scanner and have no codes. Only thing a bit unusual is the TPS shows about 0.68 at idle and Mitchell shows a minimum spec of 1.25, but I don't think this is the problem since I show 0.68 at closed throttle whether it is in the "stalling" or "running" mode.

It appears as though something is sticking when it is "cold" and then starts working properly once it "warms up!" I am leaning toward a stuck open fuel pressure regulator that starts operating properly after 20 or so starting attempts, but I am not sure how to check it.

Any ideas on how to check the FPR or other components I should be checking would be greatly appreciated.