I have an s5 turbo II and I am in the process of putting the upper intake manifold back on. I have almost everything reconnected, but there are 3 vacuum lines I didn't label and I am confused as to where they go. The lines in question are the ones on the back of the uim near the firewall. There are 4 lines, a small one on top, a big one below that, and then two more small ones underneath. Its obvious where the big line goes but what about the other 3? Can someone clue me in as to where these are supposed to go? I'll post a pic tonight after I bring my camera over.

 

These are the lines I am trying to reconnect. Anyone want to help me out? The fsm vacuum diagram I have is anything but clear about this.

 

I don't have an answer for you but you bring up a good question. Is there another source of info on re-installing the vacuum lines? The FSM, as he says, is difficult to read in this area.

 

Use the advance search funtion. Use "S5 vacuum hoses" as the keyword. Select 2nd Generation specific as the forum and then hit the search button.

 

This looks promising: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s4-s5-na-vacuum-lines-735982/

 

Yeah, that does make it a little more clear. The color coding is a very helpful touch. I wish I knew someone else in the SF bay area with a t II, it would be so simple if I could just see where they go. From what I gather the bottom line is not critical, I have heard of people stealing it for boost gauges. I just want to make sure I get the top two right. At least I got a 50 / 50 chance.

 

Ran across this post by NZConvertible which is very helpful:

Of the back of an S5 UIM are four nipples. The top three are fed from before the throttle and see no vacuum. They feed (top to bottom) the primary and secondary injector air bleeds (doesn't matter which is which) and the oil nozzles air bleed (big nipple). The bottom one is fed from behind the throttle and does see vacuum. It feeds the TB's double-throttle actuator.

On the front of the UIM are three nipples. The top and bottom ones are fed from behind the throttle and see vacuum. The middle one is fed from before the throttle and doesn't see vacuum. The top one goes to the relief solenoid valve, the middle one goes to the top of the purge control valve and the bottom one goes to the bottom of the purge control valve.

In stock form the FPR is fed from the nipple on the inside of the LIM, and I see no reason the change that.

 

My s5 JDM UIM only has 3 ports on the back. I used the middle port on the front as primary injector air bleeds. I capped the top one and use the bottom one for the MAP sensor on my standalone. On the rear I used the top one for secondary injector air bleeds, the big one for oil injector splitter, and the bottom one is vacuum/pressure source for a boost gauge or whatever.