I just installed a ported throttle body. I get a bad idle surge when i start it up then it settles back down after a few seconds. How do i make this go away?

 

My guess is the surge is caused by the learned idle settings and such from the old throttle body. I'd reset the PCM and let it go through its re-learn process with the new TB.

 

there is tables that can be adjusted for startup airflow and decay rates. if you are tuning yourself spend sometime with these tables or if you have someone tuning discuss the issue - make note of approximate air temp, engine coolant temp and how long the surge lasts