checking for vac leak

[88boostr]

hey i read somewhere that you can check for a vaccume leak by looking at your boost gauge at idle(mine is -20psi) and take off one of the vac lines and see if it changes, if it does change that means you dont have a vaccume leak, but if it doesnt change you have a vac leak, this seems like it would be a good way of testing but i am just making sure.the reason im asking is becuase im having boost problems.thanks

 

[Shawndude]

That will work for finding leaks after the throttle body on the intake manifold side, but unfortunately almost always leaks occur on the other side, between the turbo-intercooler-TB. For that, this won't work.

I find if I monitor the AFM output, I can usually tell if there is a leak because the frequency will drop (air bypassing the AFM when not under boost). Apart from that, you just have to get down there and check everything out. It's a major pain in the ass, and makes the car run like utter crap.