i need help my crx is running rough at idle. it jumps from 2000 to 900 rpms. So i replaced the iac and it does the same thing. Now if i unplug the iac it idles perfect but the check engine light comes on and it starts to run bad when i put it in gear. anyone know what this is?

 

did you get a code for the iac befor you changed it?

 

no i was just told to change the iac so i did

 

keep the iac pluged in and reset the ecu.then start it up and check the ecu for what code it is throwing.

 

i already tried that and it throws no code

 

have you drove it when its doing this?

 

yes with iac plug in it only jumps at idle. it runs ok when its at higher rpms

 

if you drive it ,it might throw a code then.some times it wont throw one till it is driven. give me a min on this.

 

did it just start doing this? did you mess with the set screw on the throttle plate,or if you tighten it to make it idle higher it will go from 900 to1500 and reat it .