OK, I adjusted the mixture as best I could, and seem to have a nice, solid idle at this point (with the new hose routing).
When I remove the top vacuum line (from the top of the WUR to the throttle body), nothing changes; pressure remains at 50PSI, and no change in engine idle.
When I remove just the bottom vacuum line (from the bottom of the WUR to the Thermovalve), pressure drops to 45PSI, but there is little or no change in engine performance.
With both vacuum lines disconnected from the WUR, I experience the same result as disconnecting only the bottom line.
There is a noticeable vacuum present on the line coming from the Thermovalve, and no vacuum present on the line from the throttle body to the WUR.
Based on my research and current understanding of the system, the vacuum system "operates against itself," so I would assume the throttle body connection will present a vacuum under hard acceleration, "overpowering" the vacuum from the Thermovalve, and causing the WUR to lower its pressure to provide a richer mixture.
I'll now wait until tomorrow morning, when the car has sat overnight, to re-test the cold control pressure, and see if these new adjustments/changes have an effect on the cold starting behavior.
Michael
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