Bad Vacuum problem...

[5OF2k]

Noted, and that makes sense. Have you done a leakdown yet? Chances are a valve isnt sealing completely or something like that, given that your vacuum readings appear normal at higher RPM; telltale sign of a vacuum leak of some sort.

-Jake

 

[DynastyLCD]

Shane, i had a local friend have that simliar problem twice. the first time, the FIAV inside the throttle body backed out and was causing a major vac leak that was unknown to us during boost leak tests, as its internal to the throttle body (this was on a 90) and his other one ended up being the intake manifold gasket was cracked slightly.

ever do the free FIAV mod? couldnt hurt to try

 

[transparentdsm]

haven't tried that one yet. i will have to check it out and maybe it is the intake manifold gasket.