I drove my crx with a d16a1 in it for the first time today. I didn't drive It above 3000 rpms. It ran perfectly. Then later tonight I took it out to see how fast it could go and reached about 7000 rpms. When I went to slow down, it stayed at 3000 rpms and wouldn't go down. I turned off the car and checked the throttle cable. That wasn't a problem. I started the car again and drove it home just fine. I didn't go above 3000 rpms again and it was fine. Anyone have a clue of what this could be?

 

Maybe check all your vacuum lines for a leak.

 

I quickly went over all the vacuum lines and nothing. The wierd part is that it only does it in gear after I up shift. It usually stays at high rpms. And if I down shift and slow down, it brings my rpms down and then back to normal.