Ported vacuum lower but not zero at idle

[mother$hip89]

The manifold vacuum is about -18 at 1000 rpm (the lowest it will idle at in park), and the ported vacuum is lower at about -10 but  thought it would be close to zero. I also have issues like the idle screws not doing anything. I looked for leaks using carb cleaner and smoke but smoke only came out the intake and the carb cleaner only made a difference in the intake(it slowed down). I also know the car runs rich at idle from the O2 sensor. The only thing I can think of is air getting past the throttle plates, but I don't know how realistic that is. Any ideas?

[blazer74]

Could be the primary throttle plates not seated or centered properly pulling the main circuit into play and/or the secondary plates not closing all the way.
Vacuum leak and/or too much bypass air possible.

[Frank400]

Increasing the size of your idle air bypass will enable you to unscrew the idle speed screw a bit, thus lowering the vacuum signal to the ported vacuum port closer to zero. 

  In fact, you should increase the idle air bypass size until you have zero reading at the ported vacuum port.  This should take care of the nozzle drip as well.

    Frank.

[Cliff Ruggles]

A few more details would help.

Engine specifications, CID, compression ratio, camshaft specs, etc?

Carburetor part number, what's been done to it, etc?

Is it an original unit or commercially "remanufactured"?

Completely IMPOSSIBLE to help out otherwise....tks....Cliff

[mother$hip89]

Sorry, I forgot to check this post. It turns out the idle circuit was blocked. Now that it has been cleared, I was able to get the speed screw out enough to get vacuum down to about -3.