Vac Leak

[Talon2z]

My brother has a 98 Talon TSI. The boost gauge typically reads -20 at idle. Once the car warms up, the vacuum jumps to -10. We've checked all hoses, connections, etc. and cannot not find anything leaking. The nipple on the fuel pressure side of the intake was what we thought the problem was since putting a finger over it stops the hissing sound of the leak. We've changed the hose on the nipple several times to no avail. Any ideas? Is it possible that the intake manifold itself is leaking?

 

[L2RTSiAWD]

Moved to Problem Diagnosis.

 

[BigBADGSX]

pressure test you setup...also make sure you check all the vac lines there are a few on the back of the intake manifold also. here is a diagram of all the vac lines on the 2g http://www.taboospeedshop.com/emissions1.htm

this tells you how to do the pressure test. http://www.dsm.org/menu.epl?item=494