Ok, I am about to go absolutly nuts. I am having an idle problem with my civic. I have an h22 in a 99-00. I just put on pullies, cam gears, and a flywheel. The car fluxuates its idle from around 500 or 600 rpms to 1000 to 1200 rpms and it just pulses as if i was pressing the gas on and off. Ive checked my vacuum and cant find a leak. Anyone that has any ideas would be greatly appreciated for I am close to dropping a 10 ton weight on my head as I would never do it to my car.
thanks

 

unplug the iacv see what happens. Is it an obd1 or obd2 motor?

 

Any check engine light? Check the codes if so..

Other than that, with the engine running, but your hand over the throttle body, and it should stall. If it keeps running, you have a vacuum leak. I would grab some soapy water and spray midly around the area to see where the leak is coming from.