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With the BAC disconnected (or the initial set coupler in place), my car can idle roughly between about 1000 and 1500. When connected, it immediately shoots up to roughly 2600-2800 (whether warm or cold). When warm with BAC disconnected, the car either barely holds or just sputters out. Obviously there is something wrong with my BAC. Is it possible that the BAC is affecting the idle, even when it is disconnected? Perhaps something in it is still open/closed and giving too much/too little air?

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Assuming that the BAC is not affecting my idle when disconnected, could this kind of behavior be caused by a vacuum leak? I've inspected it a bit and haven't noticed anything but I did have the throttle body of the block a while back and when I re-attached it didn't replace any gaskets or anything. Could this be it? What about if I have an EGR and ACV block-off plate installed, could those affect it?

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I've driven the car in this condition and it misses horribly at higher rpm's (anything above ~3500). I'm convinced my timing is off. Is it possible to set the timing if the idle is so different than stock? According to the FSM, it has to be at 850 or very close.

Sorry about the length. Any insight/experience/sympathy is welcome. Thanks.

 

Sounds like a vacuum leak. Check all hoses. You can't adjust the timing, it is fixed and controlled by the ECU.