Im having a problem with my B16 at idle, car is a 99 hatch and motor is a 92 jdm b16a. i have searched and found many different answers so hopefully someone can help me out.

I only have the problem after the car is fully warmed up, idle is high, around 1700-1800rpms and will drop sharply to 1500rpms and then back to normal very rapidly. Along with this problem after driving and having the car warmed up the car will lunge or jerk when letting off throttle and pressing back on the throttle.

i have so far
-replaced the TB gasket
-adjusted fast idle valve down, helped some but only when car is cold

here is a video i took of the car at idle fully warmed up

 

Start with this, pull off the intake air tube and look into throttle body opening. Warm the car up, while running plug the upper hole on the left side of the throttle body with a finger. Do the same for the lower hole. See if it makes a difference, if plugging either solves the high idle problem take it from there. If neither lowers idle see if your throttle plate is being held open, bad adjustment at the tb stop or tight throttle cable, if that's all good it's time to look for a vacuum leak.

I'm guessing eacv stuck, who knows. Did this just start one day? Or has it been like this since the swap?

 

Check iacv or your fuel pressure