thanx for the info again…@ colin well i have this problem i clean my acv sensor which is located behind the intake manifold i think thats waht it calls correct me if im wrong, but the wierd thing is that now when i turn my key two times when all the lights comes on in the dash before you crank the car i can hear this noice on around the intake manifold like its Gushing out air from somwhere but i can figure out where exactly its coming from…
might be your abs trying to pressurize or equalize.
i have a 91 ls coupe no abs
like a high pitched buzzing noise???..my 92 did this also i think it was comming from the IAC
edit: i didn’t read your whole post…
i think so, iono i can really explain you the noise but it sounds like if air its coming out and its kinda loud, it did this after i clean the IAC sensor which is located behind the manifold.