Originally Posted by 86civicsi
Possibly unrelated, it has had the infamous surging idle for about 2 years now---bounces from about 1000-2000 rpm. I've just lived with that. Think that may be the ACV or some other control valve or sensor.
I'll have to dig out a picture for you, there is a little air control type valve beside the throttle body with a plate on top, held on by two screws. Take out the two screws and you'll see a little peice with two notches, for a screwdriver like tool. That little thing tends to get loose after a while and cause a surging idle. Tighten it down as much as possible, and put the cover back on with a new o-ring.
That cured the problem in my old '87 Si.