Almost no airflow through Unisyn - what's this mean? Options

[smontanaro]

My /6 (original 2.0L) idles kinda rich. I decided I'd see if I could do something about it today. Got out my trusty Unisyn and my 8mm wrench. The instructions I have said to set the Unisyn based on the left rear (#6) throat and adjust it so the red ball is about halfway up the tube. Alas, I had to screw the adjuster in almost all the way to get the ball to move at all and the engine didn't stumble at all. I messed with the idle air screw to get it up to the first line (still with the Unisyn's adjuster nearly fully closed). The other throats all seemed to flow enough air to pick the ball up easily, and the obstruction caused by the Unisyn caused the engine to stumble at idle.

That suggests to me that there's something fishy w/ #6. What does it suggest to the experts among you? (IMG:style_emoticons/default/confused24.gif) (Non-experts with wild-ass guesses are welcome to chime in as well... (IMG:style_emoticons/default/biggrin.gif))

Thx,

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