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 1600-1700rpms 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.

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

 

Car?

Start by bleeding the cooling system and cleaning the IACV and FITV, if you the engine has one.

Is the CEL on?

 

its a 99 civic DX hatch, only had the car for 1 week so i'm still trying to figure out what all the previous owners have done to it

replaced the throttle body gasket because it fell apart when i took it off, adjusted the FITV down and helped some but the problem is still there. i will clean out the FITV and IACV when i get a chance on saturday

Yes, CEL is on, i think the code was 54 but i will check it again to be sure

 

looks like it had a couple of codes in the system, i will need to write them all down, had code 54, and i believe it had code 14 and 41

looks like the car has a 99 civic Si "P2T" ecu in it, don't know if that's correct or not, and the wiring looks a little weird so i guess i need to go through the harness and make sure everything is correct -_-

 

Double check the wiring from the faq section as that touches on the wiring required between obd changes.

That obd1 engine in an obd2 car with obd2 ecu

 

14 points squarely at your IACV. That's where you need to start. Test it. If it passes, pull it and clean it. If it fails, replace it. Testing the IACV is easy. Remove your intake tubing, start the car, and use your finger to block the hole feeding air to the IACV. Does your idle stop surging? If it does, your IACV has a problem. If it doesn't, you have a vacuum leak somewhere.