I’m guessing that keeping the purge valve closed during starting and warm up helps maintain that higher idle created by the air valve. I had the opportunity to bench test my original DAC2617 purge valve when it was working and can verify it was open when no power was applied. At some point my idle dropped during start up and I found the evap harness burned to a crisp near where it runs along the engine on the right side, and the purge valve dead shorted and in the open position. A long search for a replacement purge valve led me to this thread and thankfully, the normally open purge valve recommended by Jeffrey, above. I will have to report back next week as to whether the idle returns to normal (high) on cold engine startup after I replace the purge valve. I have read that some have eliminated the purge valve altogether, leaving the line open all the time. I think unmetered air through the purge valve to the manifold during start up may affect how well the engine starts and warms up since the computer is programmed to assume the valve is closed.