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Anyway, just by the exhaust smell I'm guessing that the car is running extremely rich at idle, but the meter shows it to be running lean. When I cruise it up, it'll switch to "normal" briefly, but mostly stays on the "lean" reading.
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By definition? (more like by design), a lumpy idle is caused by the engine running lean at idle due to too much exhaust scavenging. The cam is designed an rpm range far above idle, and far above idle only. That's why your a/f meter is showing lean combustion at idle.
And yes, it takes more than you might think to move the a/f ratio much at WOT. Computer controls, where you can actually set the desired a/f ratio in concrete so to speak work best. If you then examine the datalogs after changes to the a/f tables, you'll see just how much more fuel needed to be delivered to get those numbers. Amazing.