When starting I35 cold, the engine jumps to a high RPM just an instant, why?

[CMFIC]

I have an 03 I35 that I am very happy with. Question: when I start the car when it has not been running for a while, the RPMs go pretty high (at least 2k) and it sounds like you are powering up for takeoff. The RPMs stabilize quickly after that.

The car has no CEL, no issues when started, etc...

Anyone know why this is? Maybe needs spark plugs b/c too much fuel is in the chamber when starting it? Fuel injector dumping too much fuel in?

Any of the sensors, Im guessing the CEL would illuminate.

Thanks

[Q45tech]

Inorder to heat cats fast OBDII engines go to 1500-2000 immediately after cranking then rpm declines based on coolant temperature.

Remember to warm up engine until oil is at least 100F to minimize cranking wear. This means after cold cranking don't drive for 1-5 minutes depending on ambient temperature if you want to maximize engine life.