1 = Thermo-Time Switch. It's actually just a thermo switch on the pre-75 cars, but we still call it the TTS. It provides the ground for the cold-start valve, but only when the sensor is "cold enough". (Below 40F? 32F?)
2 = Auxiliary Air Regulator, or AAR. Keeps the idle from going too low when the engine is cold, by letting air go through it. Closes up when the engine warms up or when the heating element in the bottom of it warms up.
3 = Cold-Start Valve, CSV. Adds extra fuel into the manifold while the starter is cranking, if the TTS says it's cold enough.
4 = Intake Air Temp Sensor, or Temp Sensor I, or TSI. Tells the FI how warm or cool the air in the manifold is; colder air is denser and results in more fuel being injected.
You can read more about the way this system works here:
http://members.rennlist.com/pbanders .
--DD