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jwasbury jwasbury is offline
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Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,384
Disabled the Decel valve and now AFRs are higher...why?

I'm testing out how the car does without the decel valve, so I have temporarily disabled it by pulling off the vac line and plugging it. Car runs and idles great...and my initial impressions are I prefer it without the valve. I did notice that my AFRs seemed to go leaner with the valve disabled, and I'm trying to reason out why this would happen. Before, my idle afr was around 13.5 (going for 2.5% CO). On the test drive after disabling the valve my idle afr is over 14.
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930
Old 10-10-2008, 08:14 PM
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