Hey when i start my car the rpms go to 2200 and then go down to 1500 and then go up to 2200 again over and over again. And it stays high until my car warms up. when it does the idle goes to 700 and stays there and the car drives fine. Does someone have any idea wats going on?

 

Check the stickies for the Engine Coolant Temp Sensor testing.. it will normally throw the Check Engine Light but if its not fully dead it will just supply bad output for the ecu hence the RPMS going up and down as the ECU things the engine is too hot or too cold.. this sensor is different to your dash temp gauge

 

Clean out the throttle body and IACV.

It is normal for your car to idle higher (max of about 1500RPM) when cold. As the car warms up, the idle will slowly drop down to the 550-700 range (depending on auto or 5spd).

 

Ahh but this bit is not normal is it "go to 2200 and then go down to 1500 and then go up to 2200 again over and over again."

 

i looked in the stickies and i can't find one about the testing of the coolant temp sensor. I have recently cleaned my trottle body. i'll try the IACV, but i don't think that its the problem since it goes away when the car warms up. anyone else got any ideas?

 

anyone?????

 

Have the same problem just not all the time, going to dealer tomorrow, will let you know after

 

After you do the above see how it starts and idles. If the idle is still up over 1500 RPM's you'll need to adjust the cold idle linkage. There is a plunger down under and to the right on the throttle body. That's the cold idle boost linkage. There are scribes on the cam and follower on that linkage that should be in line when the engine is cool. The Haynes shop manual has a good picture and description of how the cold idle is adjusted.

 

mine does the exact same thing as you are describing. seems to do it much more often in the winter months. changed the engine coolant temp sensor and made no diffrence at all. throttle body cleaning also made no difference. next steps i will try is cleaning the iacv and to check into that cold idle plunger suggestion

 

I agree. I had the same problem on an old honda. They called it a thermowax plunger. The car would just rev itself over and over until it got warm. For that car, the part was 40 bucks and pretty easy to replace.