Intake Manifold question

[Livinloud11]

So I have a 95 civic and it has been having that idle surging when its cold. What stopped it actually without messing up my idle is when I plug up the bottom hole in the intake manifold. If I plug the top hole it wants to die or about dies. So my question is if plugging the bottom hole in the IM makes my car not have a bad idle and makes it run decent, whats causing that problem to begin with?

 

[sohclubkid]

vacume leak perhapse

 

[AlaskaB16]

Are you saying you have open vacuum line ports? Has it always been like that? You might want to be sure what they go to and hook them back up so it can run correctly. Some you can plug, other should remain connected but none should just be left open to atmosphere. Post a picture of the ports in question. Also, Google the vacuum lines for the motor you have and I bet you'll find a photo of what others are doing or OEM set up. Good luck

 

[Livinloud11]

I don't think im missing any vacuum lines, but im not crossing it out. Theres no open plugs or anything I just blocked off the lower hole in the intake right by the throttle body. Ill look up a vacuum diagram but im just confused on what else it could be.

 

[Livinloud11]

I took apart the fitv cleaned it and tightened it and put it back on, I took the thing I had blocking the bottom hole in the IM out, and now here I am. I dont know if it will still fluctuate when its cold, ive replaced the IACV numerous times by the way, and the only other thing bothering me is with the AC on and everything if I hit the gas sometimes the RPMs drop for a second and then rise. What is wrong with my honda. I can't find any vacuum leaks either.