06 Sonata V6 cold start

Somewhat colder weather has started settling in and my 06 V6 Sonata (<5000 miles) is doing some new things on a cold start.
Normally it fires up and holds around 1100rpm. Now, it's jumping
above 2100rpm and holding that for five or ten seconds. It's something like what would happen if you started it with your foot on the gas, which I am _not_ doing.
So what's the issue? I always heard that it was never a good idea to rev a cold engine because it promotes carbon buildup. And anyway, the car didn't do this in the summer. Is this normal cold weather behavior for a Lamda V6?
I am also still getting some sort of vibration at idle which feels and sounds like a classic misfire. It's plainly felt from the driver's seat and heard audibly out the exhaust pipes.
At the 3500 mile oil change, I asked the dealer to check that and they said they found nothing abnormal.
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This is normal operation in colder weather for any car. At colder temperatures, the engine must run faster to run well. As the engine warms, the idle should lower.
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It may be normal operation, but, it is unnecessary for it to idle at 2100 rpms when cold outside. I had this same incident on my 2002 SantFe when it was new. It bothered me to see it immediately rev to 2100 rpms when it was started in -20 f . temps. I took it back to my Hyundai Dealer and was told 'it was normal for Hyundais' . I since found out how the Idle Device (for lack of the technical definition) works ; I very easily removed it (2 screws and a clip) from the top of the engine and made a solid template (gasket) out of light gauge sheetmetal to exactly match the size of the flange of this Device. I then proceeded to drill two new holes in the middle of the template which were roughly half the size of the existing holes of the Device . I reinstalled the Device with the Template in between , and wullah...she idles at 1100 rpm, when cold, regardless of ambient temps. Absolutely no driveability problems, or codes, and it gets 1 mpg better fuel economy. Plus, you cant even tell the Device was modified.
This proves that cold revving at 2100 rpms is totally unnecessary , and if it takes a bit longer to warm up the car on a cold day, id rather have it that way .
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PMDR wrote:

This is for fuel mileage and clean air reasons. The faster the engine warms up the faster it's operating at it's most fuel efficient temperature with the leaast emissions.
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