This reply comes quite late, but Brian, if you are still experiencing a hunting idle, have your lambda cycle checked. It could be that your car is running too lean. I have had a similar problem and it was caused by an inproper air fuel mixture.
The root cause of the problem was actually a faulty ignition coil which didn't produce enough voltage and therefore didn't burn the air/fuel completely. When sitting at a stoplight, this allowed the mixture in the combustion chamber to go into an overrich condition which resulted in bogging and hesitation off the line. But only when sitting idle for a few minutes or while the coolant temp was low.
To compenaste, the mechanic adjusted the mixture lean. This eased the bogging problem, but caused an idle search.
Once the root problem was traced, the mix was adjusted to the proper setting and there has been no trouble since.
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