HELP: Sensors for Megasqurit (EFI)

Hi

I’m about to install MegaSquirt on my Galant which was originally a 1800, but now a 4G63-T and I have some questions on where the different sensors are located, and which pins to connect the different wires to.
The air and water temp. sensors are easy they are signal and ground. But which water temp. sensor are for the ECU, the sensor at the top of the thermostat housing or the one at the bottom.
What are the 4 pins on the camshaft positioning sensor for??? A Hall sensor normally has 3 pins.
What are the different pins on the idle air control valve for???
And last, what are the different pins on the Ignition module for?

 

[jepherz]

I believe the temp sensor on the top of the housing is for air conditioning???

There is more than one output on the CAS because it also outputs a "crank" signal as well.

 

[punisher]

http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_4g63_powered_dsm_eclipse_talon_laser.htm