I have a jdm b16a first gen. It idles at 1200 rpm when you start it up on a first cold start but when the temperature heats up on the motor it idles at 500 rpm. Is that normal? How do I fix this!?!?

 

I'm actually having this same issue at the moment on a stock HF and im stumped after checking for cracks in hoses and cleaning the IACV and bleeding air out of coolant.

 

It is supposed to do that. It helps the car warm up quicker. It is the IACV and is controlled by the ECU. As long as the idle isnt hunting or jumping around or way too high then it's normal.

 

Isn't the normal idle for this motor is 700 rpm?

 

Somewhere around there. But they idle higher cold. Also, it is not unheard of for factory tachometers to be off by 2-300 rpm.

 

Oh okay so my tach metre could be off by 200 rpm?

 

Adjust the idle screw on the throttle body, on both the HF and the b16.

 

As F22 said, your idle sounds normal. It will be higher cold and lower warm. Mine usually idles at 700 warmed up, but sometimes will be as low as 3-400 indicated. It depends on weather and electrical load. Older cars will vary on this, most newer cars are more consistent. If you are not throwing a CEL and it's anywhere near 1000rpm, you are in good shape.