This problem just started on my 350 TBI engine. Sometimes on the first start of the day the engine will start but will not rev up as usuall when it is cold. It will die or idle really low unless I step on the gas to keep it running. The problem does not happen after warming up just on the first start.
Another weird symptom is when this happens on start-up if I turn turn off the engine then start it back up and it revs up like normal when cold. It's like I have to re-cycle the start. It's also hit or miss on when it will do it.

 

Sounds like a sticky IAC.

I've also seen the IAC's connector/pins go bad over the years. Had one car that when you stepped on the clutch it'd rev up to about 3500 after you'd been driving! Hop out, wiggle the connector and down it'd come. Way embarrassing.

 

Were is the loaction of the IAC connector? What is definition of IAC? My 89 TBI Formula has no high speed idle after sitting all winter. Your input is much appreciated.

 

The IAC (Idle Air Control motor) is located on the passenger side of the TBI unit, pointing slightly backwards. Usually has a square 4 pin weatherpak connector.

Since the electrical portion of the connector is a pin/sleeve affair, I think what's happening is that they're just being squished open/pinched closed over time from being vibrated, heat cycled, and laying on there side.