Does a cold startup require more fuel, than a warm startup? I notice that when I start my car cold, the AF is in the low to mid 13's. Does a cold startup require more fuel? I would think it would require more timing because it needs to reach proper cylinder temp. Can someone fill me in. Thanks!

 

Yes cold startup requires more fuel because some of the fuel condenses on the cold engine parts and doesn't contribute to combustion. The liquid fuel is passed out of the engine unburned. The idle is higher as well to overcome frictional drag from cold oil and tight fitting parts.