Ok, my car is driving me crazy ...PLEASE HELP !

[UndertheOcean]

Had to replace the headgasket on my 1992 honda Civic LX (4 doors,Automatic) a few days ago , and at the end everything seemed fine and dandy until the engine warmed up , it then started to fluctuate continously betweem 1000 and 1500 rpm while idling on Neutral or Park ... wehn its on Drive it seems to be working ok.

The funny thing is that turning the AC on seems make the problem go away, so does disconnecting power from the EACV unit... but I'm not convinved that the EACV is bad because of the AC thing.

Can the mechanically inclined help ?

its driving me crazy.

[jobycom]

1. My 89 civic did that when I rebuilt the head, too

I don't remember how I fixed it, but I remember checking all the vacuum lines and various pollution stuff. Check vacuum lines for hissing or breathing noises. Pull a few off and see if the noise gets better or worse. Make sure the EGR valve is working. Wish I could remember what I finally did, but I can't. But that's how I went about finding it. I also had a Haynes manual to show me what was what, and looked up some things on the Internet.

That effect is called "loping," and you can probably Google it for some ideas, too.