I did this on a 90 2.5 turbo ~8 years ago so do not remember exactly, but.....

Look at parts 707 on the diagram. As I recall was referred to as Y31/1 & 2 and one of them provided vacuum for the wastegate. They are located just behind the right headlight on the lower firewall.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=124133%5F15S&M=603%2E960&GA=722%2E357&CT=M&cat=503&SID=14&SGR=135&SGN=08

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)