Alright so I just did my first bseries swap on my 96 civic hatch (jdm b18c) and I’m having this problem where when I first start the car it goes to 3000rpm and kinda just stays there, not jumping up and down, just sits. I’m running the y8 harness so it’s plug n play, skunk 2 intake manifold with a 68mm blox throttle body (has thermal gaskets) new iacv, lots of new parts. I’ve check for vacuum leaks and I’m not seeing anything that I might’ve missed so I’m just confused. I seen that my idle adjuster is tightened all the way which is weird bc wouldn’t it run at a lower rpm or not run at all? Anyways I’m really confused and annoyed. Could it be a vacuum line I might’ve missed?

 

Did you leave a slight bit of slack on the throttle cable so throttle plate is fully closing? Do you have another iacv you could put on there to rule that out as a possible cause?