VACUUM LINE REROUTE
Ok, so now you have a stock route diagram and I have shown you how to remove the vacuum lines from the rubber couplers, so let’s proceed to the rerouting. I found a way to simplify the vacuum lines without cutting and capping them, but first let’s trace out the lines we are going to modify.
So with the EGR valve & solenoid removed, we have to contend with the vacuum lines that were left behind. If you remember earlier, we disconnected them and simply moved them to the side while we removed all the hardware. Well the green “EGR” vacuum line is now disconnected at both ends, so there is no need to trace it. That leaves us picking up at the red “EGR solenoid” vacuum line that shares the black coupler that was once plugged into the EGR solenoid. We follow this line around to the front of the engine. I have traced its route (purple drawn line) in these pictures:
Here is a close up shot of the solenoid vacuum line (in wire loom still to help distinguish it.)
You can see that the line comes to one leg of a “Y” coupler (purple arrow). The other leg of this “Y” coupler (yellow arrow) goes up to a coupler in the plenum.
The “Y” coupler serves as a split to provide vacuum to the solenoid. With no solenoid, we don’t need this split to supply vacuum to the line anymore. So this solenoid line (purple) can be removed from the “Y” coupler as I detailed earlier. Another option is to simply cap it and leave the rest of the vacuum system alone or even do what I did and streamline the vacuum system... the choice is yours.
Instead of just capping the now unused vacuum solenoid line (purple drawn) or just removing it from the leg of the "Y", I took things one step further. What I did was leave the line (purple drawn) in the "Y" and focused on removing the now unneeded couplers as well. I removed the short line (yellow) from the plenum coupler. I then removed the line (orange drawn line) from the base of the "Y" coupler. Now if I wanted, I could simply plug the now freed orange drawn line into the plenum coupler and be done.
So, if I was the average person I would be done now, but that's not me. I decided I wanted to shorten this line, (orange drawn line) before I plugged into the plenum. I wanted it to run tucked under the plenum instead of running out past the fuel rail and out to the valve cover like it did stock. Since I already knew the start of the line, I just had to find where it ended to be sure I could easily remove it and swap it out.
I traced the line back to yet another “Y” coupler. Our line feeds into the base of the “Y” and then splits off into 2 other vacuum lines. So it should be as easy as removing the stock line at the base of the "Y" and adding the shorter line in its place.
Just to be sure I would not screw up anything by swapping to a shorter line, I traced out the lines that the "Y" coupler fed. I traced one line to the fire wall and the other goes down into the passenger side fender well corner (pink drawn line). The lines had plenty of spare length, so I would cause no harm in swapping the plenum line out for a shorter one.
I have now isolated a good coupler joint to remove and swap this line (orange drawn line). It would be easy to replace this long line between the 2 “Y” couplers. If YOU want to, you can simply cut the existing line shorter before you plug it back in the plenum coupler. I decided instead that I wanted to do it right and replace it altogether with a shorter line. Remember, I like to keep things so I can swap them back to stock if needed, so no cutting lines for me. I thought about it and even had 2 perfectly good lines available to use should I have decided to replace them. The old solenoid vacuum line was too long, but the EGR vacuum line looked to be just right. The molded curves in it actually suited my reroute anyway.
So I removed the green EGR vacuum line from its coupler and I set it to the side to be my donor.
I had previously disconnected the orange drawn line from the front of the engine via the short (yellow) line at the plenum coupler. Now, I just had to remove it from the “Y” coupler at the other end to be able to remove it from the car completely (circled).
So here are some pictures to visually explain what I have been describing…
What we have (left):
Where we are going (right). Blue is discarded..
Once you have removed the vacuum line (orange drawn line) from the "Y" coupler, you can take your old green EGR vacuum line and orient it to fit in the couplers. I found that you need to stick the straighter end in at the “ Y” in the rear most position and the more curved end will now go in the plenum coupler at the front of the engine.
The plenum coupler has another line that comes out of it and this one we will just leave as it is (red one in pic). I covered the green EGR line in wireloom.
I have marked it with a red line in the following picture. This line goes to the fuel regulator and can run its vacuum line anyway you see fit. You may leave it as it is, run it to the front, rear or even under the fuel rail.
Here is the line running to the fuel sensor on a friend's car (red out of the loom):
In the end, you will have routing like this diagram if you have simplified things as we did.
Here are a few of our after pictures of the lines…
The plenum line running to our fuel regulator:
The other plenum vacuum line, now shorter… The X-EGR vacuum line tucks things up closer to the TB, versus running down past the fuel rail.
Here it is coming out on the backside of the plenum, going in the “Y” coupler:
An overall shot...