Okay so my buddy has a 92 teggy with a B20 swap, integran intake manifold on it. Has a short ram on it too. So i know that it is not the intake pipe because i know what that sound is, this one is coming from the driver side of the intake manifold. It is not a deep sucking sound like that of the intake, more of a soft hiss. When we turn it off you can hear the suction of the intake, once that has stopped you can hear a leak of some sorts, like air from a tire. Any idea to which possible vacume hose it could be'??? I have checked the ones coming from the map sensor, also the one coming to the top of the fuel pressure regulator. Any suggestions would be great!! thank-you in advance.

 

if its a vacuum leak your idle would probably jump up and down......

correct me if i'm wrong.

 

well the idle does go wonky sometimes. But at other times its fine.

 

I have the same noise. I dont pay any attention to it. It couldnt be a vacuum leak because the car is off.