I used a hodge podge of photos that were originally taken for different reasons and from different cars, so the pics here do not always get my point across as well as I would like. But if the reader follows the instructions carefully, all the connections for that rat's nest of vacuum tubing in front of the battery are explained here.
A solenoid is defined as a device that translates an electrical signal into mechanical movement. In this case, the electrical signal is coming from the cars computer (ECU) via the electrical engine harness. The mechanical movment is opening and closing a vacuum path to the connected tubing.
The solenoids are the same for the AIV, EGR, and PRVR. The red arrow points to the TOP nipple, blue arrow to the MIDDLE nipple, and the yellow arrow to the BOTTOM nipple on top of my thumb. The red circle was where the electrical engine harness connected to the solenoid.
Red X battery tray. Green circle AIV solenoid. Red circle EGR solenoid. Yellow circle is the TOP vacuum line from AIV solenoid T'd into boost gauge hose, then to nipple on balance tube.
Yellow X above is on the mounting bracket for both solenoids. The mounting bolts have been removed.
The yellow arrow shows the balance tube connection for the boost hose and the TOP AIV vacuum line. The AIV line is not shown in this pic, but is normally T'd into the boost line as shown above. The vacuum line at the green arrow leads to the passenger side recirculation valve, at the front of the car.
Looking at the rat's nest of vacuum lines that came off these solenoids and it is easy to see why I deleted both of these systems on my car.
The AIV solenoid is in hand, still attached to its mounting bracket. The yellow circle is same as above pic - T connecting boost hose and TOP EGR hose, leading to balance tube nipple.
Red circle above is the T from the MIDDLE AIV nipple, which leads to the R & L AIV's in both fender wells. The BOTTOM AIV nipple above T's into the TOP nipple from EGR solenoid below, then connects to hardline galley on side of plenum. Red dot above shows BLACK engine electrical harness connector, compared to the WHITE harness connector below for the EGR solenoid.
Here is the EGR solenoid still connected to the mounting bracket with the bracket lifted from the car.
In the pic above, the yellow mark is on the TOP EGR nipple vacuum line, which is T'd to BOTTOM bottom nipple from AIV solenoid above, then to hardline galley on side of plenum. The green mark is on the MIDDLE EGR nipple vacuum line, which goes directly to the EGR, shown in the next pic below. The BOTTOM EGR nipple cirlced in red goes to the hardline galley on the passenger side of the plenum. The red dot is on the WHITE electrical harness connector.
Notice again, the AIV solenoid took the BLACK harness connector, and the EGR solenoid took the WHITE harness connector.
The MIDDLE nipple of the EGR solenoid is connected to a hard line near the rear passenger side of the plenum. The white battery tray is in the lower left corner.
The hard line at my fingertip above leads to the rear of the engine and is connected to another vacuum line shown below, and then to the nipple on the EGR unit itself.
This small insulated vacuum hose goes between the nipple above and the red arrow in the pic below.
The red arrow on the right side of the pic shows where the middle nipple from the EGR solenoid ultimately connected.
There is a metal rail or "galley" on the passenger side of the plenum that is simply straight hardline extensions to bring the vacuum tubing from the solenoids to the forward part of the engine bay.
The hardline galley is cirlcled in red. On stock Z's, these hardlines are under a black plastic cover that I removed.
The white and green arrows above show the two vacuum lines coming from the solenoids on the left side of the pic, being brought up to the front of the engine bay on the right side of the pic. Ignore the yellow circle and arrow which show the passenger side VTC solenoid connector. The front of the engine is toward the right side of the pic.
The TOP nipple of the EGR solenoid (which is also T'd to the BOTTOM nipple of the AIV solenoid) is normally connected to the BOTTOM of the two metal hard pipes on the metal galley above (the green arrows). It doesn't really matter which hardpipe on the galley is used for which nipple on the solenoid(s), as long as it is consistent to the connection in front. The vacuum hose coming out at the green arrow on the right side of the pic goes down to a nipple on the large, round black hard plastic air intake tube, shown below.
The BOTTOM nipple of the EGR solenoid is normally connected to the TOP metal hard pipe on the galley (white arrows). Trace this forward and their should be a vacuum line at the other end going to underneath the front of the THROTTLE BODY on that same side. To get to this connection you probably have to remove the large, black, somewhat soft, intercooler intake hose that is connected to the throttle body.
My finger is pointing to a capped nipple on the passenger side throttle body, where the TOP nipple from the EGR solenoid ultimately connected. The yellow circle in this pic is the same nipple cirlced below.
The intercooler hoses on the passenger side were removed for these pics.
Another view of the same nipple circled in yellow above, which is where the BOTTOM nipple on the EGR solenoid ends up.