i was oputting on my intake(AEM short on a (94 Civic DX motor) and i noticed a hissing sound coming from the throttle body (where the intake pipe attaches to). when i looked into it there
are 2 holes/ports inside the throttle body on the side away from
the engine, and the upper hole.port is causing this noise.
i know some intakes whistle while running but this is
not from the intake itself. does anyone know what
this hole is for and if it is a problem to have it making this noise. in the pic below its where the red circle is

thanks
Originally posted by inspyral

[QUOTE]Originally posted by inspyral

 

that seems normal. You might have to adjust that little screw on the throtle body. When i turned mine way up you can real hear it.

 

that hole is most likely the one that goes to the IACV to control your idle speed...

 

all intakes seem to make hissing type noise, my friends civic made a loud hissing noise and my GSR does too.
but mine is supercharged so i expect to hear it sucking in the air.

 

how do you control the idle speed?? what do you turn do increase/decrease it?

 

The IACV uses coolant temp as a reference to idle the engine faster until it warms up, then it lets the ide speed drop to the normal idle RPM. Your base idle can be adjusted with the slotted screw on the top of the throttle body. Turn the screw in to lower, out to raise idle. Do this when the engine is warm, with all accessories turned off.