I am trying to figure out the purpose of the vacuum line that runs with the return and feed line. I see that it goes to a diverter valve that eventually leads to the TB on the passenger side of the intake. However, I see no sings of an evap can. Is there one hidden or are there vapaors that are drawn back to the tank without an evap can? I become currious when I noticed that it was not plugged in.

Here is a pic of the line in question.

 

That is the purge line for the EEC system carbon canister in the driver's rear fender. The canister collects the fuel vapor from the tank vent. The purge solenoid on the passenger side intake manifold bracket open periodically to pull air in through the "3rd line" and pull the fuel vapor out of the charcoal, so it can be burned in the engine.

Shoebox's tech aid:

http://shbox.com/1/evap_system.jpg

 

Awesome thanks. I figured as much. I didn't realize though that it worked when the car was on.