Vacuum leak through throttle body? Any ideas?

[mexaspire]

Hi guys! I'm back to square one. I have a heavy vibration at idle, with and without the AC.

I sometimes get P0505 which is a IAC symptom.

Today I was blowing smoke into the intake to see any leaks and the only place I could see it coming out from is the side of the throttle body, where the spring for the accelerator wire and such is. This would certainly inject unmetered air into the system, causing a rough idle. I am not sure this can happen. Any ideas?

[WmWatt]

You should be able to verify by misting the suspected area while the engine is running. I've read here two ways of doing it. Misting with starter fluid spray will cause the engine to rev. Misting with water from a plant mister will case the engine to bog.

[mexaspire]

Will try both of those and report back. Did squirt some carb cleaner around the throttle spring area and did have some light acceleration but could not replicate it.
Thanks again!

[ricko1966]

I believe po505 is IAC unable to control idle speed, which could be a bad IAC a vacuum leak or whole bunch of other things.Kind of like when you get an oxygen sensor out of range code sure could be the o2 sensor,or the o2 sensor us fine and out of range due to an exhaust leak,a plugged injector etc.etc..Your IAC could be trying to regulate idle on a car that's trying to run on three cylinders because it needs a new distributor cap etc. My opinion is it would take some really really sloppy throttle shaft bushings to cause you a problem.