Idle Air Control problem/check engine light
 

99 civic check engine light is on and it idles rough and sputters during early light acceleration. (if battery is disconnected to reset computer it runs perfectly fine for 30 minutes no check engine light)

Scanned the computer it only has 1 code I'll have to rescan it at autozone tomorrow to get he code number.
It sais possible causes:
1) Dirty Throttle body (It was spotless but I cleaned it with carb/choke cleaner anyways)
2) No power at Idle Air Control ( I checked it for power and it has 12.4 volts)
3) Vacuum leak ( I hooked up a pressure tester to the brake booster line where it comes off of the intake manifold and it had steady vacuum)
4) Faulty idle air control (this was the last thing I did because of its price)

Ive covered everything the code calls for and it is still throwing the code and idling rough

Did you try cleaning out the IACV? That is what I would try next, if you haven't already done so.

As for the TB, did you just spray carb cleaner in or have you actually dug in there and wiped everything clean?

I only sprayed it and worked the throttle plate back and forth it was extremely clean anyways. I will take it off and scrub it if that even "might" fix it. I cleaned the port out on the inside of the throttle body where it enters into the Idle air control. Ive already replaced the idle air control.

What code are you getting?

code P0505

When I disconnect the battery and clear the code it runs fine for 30 minutes. Then the check engine light comes on and at the same time it begins to idle rough and sputters under light acceleration.

Ever get this problem cleared? I am having a similar issue.

I had this kind of problem about a week ago. Basically what I ended up doing was took out all the air intake system, as to look at the throttle body fully. I took the Idle Air control valve off to see if it was dirty, and for the most part it wasn't. however, I took a look at the little gasket that is between the throttle body and the IACV and it was in pieces... Completely broken. So, only place I know that could get me this part was a genuine honda dealer with a service center and had them over night the part and I went and picked it up. $2.24, cheapest car fix I have had. Now, no Idle problem at all! Check that gasket it's a tiny part but that plays a GIANT roll in how the engine runs.

I'll give it a shot. Thanks a bunch for the reply.

If I were you I would look into the MAP sensor. sounds similair to that. it is located behind throttle body off to the right, it is a small sqaure that has a vaccum line leading into it. If that does not fix it then clean IACV, if all else fails...Seafoam the **** out of it.