EFI config, 4.2 with Weber type throttle bodies

Hi, I am looking at doing an EFI conversion on my S2 4.2. Planning to use throttle bodies that look like webers. This means 3 throttle bodies with 6 ventirues.
I have figured out how to do the TPS, ECT, Air temp and MAP vacuum sensors… but I cant figure out how to set up Idle AIr control, Brake vacuum or PCV vacuum ports with the individual throttle bodies. Anybody done solved these problems before?
Thanks

You run into a similar problem that ITB’s do. in order to get a reliable vacuum for brakes and idle control you would likely need to make a vacuum manifold that connects to each throttle body. That seems to be the most common solution. Its what i am planning on doing for my custom itb setup… when I eventually get around to making it. although for idle control you would need to have a seperate manifold to “inject” air after the throttle bodies.

Thanks William.
So, thats one manifold for MAP, another for IAC and a 3rd for Brake vacuum? Thats a lot of plumbing! Maybe I wont go with IAC for cold start… just use a manual fast idle like a the old choke with the ECU handling enrcihment. Do you think that could work? cheers

I would assume that you could combine the MAP and Brake manifolds into one, but I don’t have real-world experience to back that hypothesis up.

Again I don’t have real-world experience (yet) but I believe that is a possible route, depending on the ECU used. There is another guy in the V12 section that is making custom ITB’s that seems to be more adept at it than I am. Maybe send him a private message. Designing my own ITBs? - #102 by Nigelplug