Okay so I have looked everywhere for an answer to this question and have found nothing. So here is the situation I have a 95 civic that I recently purchased and it had an idling problem and the motor was bad. It was a z6 originally. Yesterday I swapped the motor with a d15b and used the z6 intake manifold etc. I believe they are both the same but the car runs but it has a low idle and when you lightly give the car throttle when it gets around 1500rpm it sounds like it hits a rev limiter is the only way I know to explain it it just bounces up and down until around 2000 rpm then it clears up through redline. It threw a code 14 for iacv and I swapped over the iacv that came with the d15b and it ran like a top for about 15 minutes and then it went right back to running as it did before. Still throwing code 14 so I don't know exactly where to turn next. If anyone has an idea please let me know.