Ok, i have an ls/vtec motor in my 96 hatch. I have had a idle problem for a while where cold starts rev to 3500 rpms and slowly drop as it warms it. Now since i installed my hondata launch control, it idles from 1000-3000 rpms eratically. I took out the wires goin to the s200 box to disable the feature and it still does this. it does not go away either when it is warmed. What could be the problem!

Well, i have a p28 controling a gsr top end which means it has a fit valve. Can the p28 control that? (i am almost positive it is a p28). I was planning on takin out the fit valve and screwing that screw in, but now im not sure if thats the problem. Any advice. I dont think its the iacv, but it could be.

 

check for vacuum leaks, do you get a cel??? if so what kind ???
if not i think its a vacuum leak

 

no cel, and check this. When i am at 3000 rpms it is at 20 hg of vacuum, and at 1000 it goes towards 10hg of vacuum. That seems oposite of what it should be.

 

are you sure that it goes up?? i have the same thing but when the vacuum is droping the eacv is opening and correcting the vacuum but in my case its a vacuum problem ......
what is your set up turbo? mine is jrsc and i have a leak between the charger and the manifold.

it goes from 1000 to 2000 rpm so could be the same

 

problem solved. It was the fitv!