Hello, I just recently bought a 2000 civic ex and it had a check engine light on P0505. I bought a new IACV and replaced it, it ran better for a day or so then the CE light came back. I found out that the cruise control vacuum line was disconnected creating a vacuum leak, but whenever I plug it back or plug it the engine idles near 0 rpm or dies. Can anybody help me figure out why it does this and how to fix it? Another thing is that when the car warms up(about 10 min) and I press the gas or let off the gas, the car jerks. Any help is much appreciated thank you!

 

Make sure all your vacuum lines are good and reset/re-adjust your idle.

 

I tried to reconnect the cruise control vacuum line and do an idle relearn but the car still idles near 0 or dies.

 

disconnect the iacv and what happens?