Have you noted your fuel flow at full rich and leaned when taxiing?  Perhaps it is a problem with my instrumentation but I've done this with my Lyc IO-360 and have seen no measurable drop in fuel flow.  Any throttle position above a stuttering rough uses the same fuel.

Robert,

 

I have not monitored the fuel flow gauge carefully during this phase.  It is about 1.5 GPH at 1000-1100 RPM.  If I spend the time, I do see a rise of 20-30 RPM if I lean to "peak" RPM.

 

Stuttering - something's wrong.  I am operating with an electronic ignition (LASAR), fine wire plugs gapped more open than normal, .022 shrouded injectors that deliver cruise EGT peaks within .3 - .5 GPH (GAMI Lean Test) and other adjustments.  Thus,  I believe I have achieved a reasonable balance of the required 3 S's - Spark, SFuel and SAir - throughout all normal engine operation.

 

I will try to get the FF info today (weather permitting - it's freaking cold here) as best I can as reported by the VM EPI800 engine monitor.