I've been reading just about every post on "Dies at start", "Bad Idle", "Idle speed" and never quite wrap my head around what's mechanical and what's electronic that can make an engine perform poorly in the driveway or on the road. So far I've figured out:

Mechanical: EGR Valve, Throttle body, Idle speed adjustment screw,
thermal valve on thermostat housing, thermal valve (for EGR vacuum)
under intake manifold

Electronic: MAF, throttle position switch

Not Sure What it is: My 2.6 I-TEC has what's been refered to as an air regulator with a large black tube that goes up to the throttle body and acts as a bypass to the intake manifold. As near as I can tell it actuates at a cold start and closes after a few minutes and it appears to be electric/electronic. I might call it a cold idle air control valve or on another day a fast idle air control valve, but it's real name is probably air regulator. It's got nothing to do with setting the idle on a warm engine because it seems to become inactive after a few minutes, but I have to think that for all of us complaining about engines that die on start-up, it may be something to explore. For those with more know how: Is it a device that sends/ receives a signal to/from the ECM or is this another thermal mechanical device that simply closes after a few minutes of acting as a virtual choke?