I have figured out most of my vacuum lines thanks to the diagram on the underside of the hood, however I cannot find where the line from the PCM is supposed to go. Also there is a switch on the right side fender just by the firewall that has several vacuum lines going to it as well as some wires, anybody know what this is? (see pictures)

 

Are the ESA and PCM the same thing?

 

If I'm right it stands for Electronic Spark Advance. There is no mechanical or vacuum advance in the distributor. Still running it on my 87 at 173,000 miles with no problems.

 

The device in the second picture has been used as an EGR solenoid and/or a purge control solenoid and/or ASRV/PVH solenoid depending on the year and engine. From your diagram it looks like it is the purge control solenoid and the ASRV/PVH solenoid.