FYI,
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I found this post on a different forum and I am 95% this is the problem;
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Have you guys checked the AFM? It sounds like their could be a dead spot in the door sweep signal, so that when the door sweep movement in between certain points in the AFM gets a bad reading.
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That would cause it to run lean for that second, which would cause the bucking and hesitation you guys are talking about between the RPM's which correspond to the dead spots.
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You can check the door movement with an oscilloscope
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(a high end autoranging multimeter my work too), but if you know someone with a known good AFM it may be easiest to install that and see if it works.
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Makes perfect sense why it works fine at idle and bucks through the rev range, also explains why it only happens when hot, engine runs off lambda in closed loop not AFM when cold and in idle.
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95% this is the problem so try it if you still are having trouble!