Funny Revving While Warming Up

[KungRolla]

Hi guys,

My car goes thru a few phases while warming up. For the first minute of warming it up after starting it, stays at relatively normal 1.5 rpm. For the second minute, it shoots all the way up to 2k rpm. From then on, it does mini revs about 300 rpm worth upwards then downwards until it reaches under 1k rpm. Looked up on my Haynes manual... doesn't address problem? Wutcha guys think it is? faulty air sensors? fuel? What should i first look into to find out the problem?

Thanks

[Flashmn]

if its only in the warming up process I wouldnt worry too much about it, heck my car is awfully weird while warming up...

[toymaniac]

my 4 age does that as well as my 4af and my 4ac did also that .....and i had no problems whit these engines....

[ek-9]

you car does that so warm everything up properly. it'll idle differently to compensate for different conditions.

[REN69]

mine used to do that until i replaced the airbox and put on a cone filter.. but now it just sits at 2000rpm and comes down to 1000 after a while.. then if I run it for a bit.. it goes back to 1500-2000 rpm and just sits there.. I know it's not because of not enough air... I'm gonna get my timing adjusted and see if that does it (everyone said I should check the timing)

[Migsman]

There's many many sensors that all act in conjuction with another when the car is warming up. If the idle isn't bouncing at standard operating temperature you should fine for now, but I'd look into it

some sources for the problem...

AFM
Coolant temp sensor
Throttle position sensor

Migs

[KungRolla]

whew... that worried me a bit... but i'll look into the AFM, coolant temp sensor, throttle position sensor as Migs says.

thanks guys,