1998 Civic Idle surge, 1k to 2k

Hi again folks. Same car as the no start after timing belt change.
Once running, I found that the a/c wasn't working. It was working when my son sold me
the car. So, off it went to the local garage for a/c check and safety inspection.
When I first brought the car to him, I had the surging. I found that the valve cover gasket was broken at one corner and hanging out. I intended to fix it after the a/c work and inspection.
When my mechanic was working on the a/c, the surge messed him up because the a/c compressor kept cutting in and out due to the low idle speed. So, he pushed the gasket segment back into place and put RTV around the break to stop the vacuum leak. It worked and he fixed the a/c.
Soon after I picked the car up, the surge started again. I bought a new gasket set, and installed it. It STILL surges !!!!!!!!!!!!! arrrrgggghhhhh !!!!!!!!!!!
I cleaned the throttle body and plate a bit, didn't help.
I've googled this to death and several things came up. One was that someone had a thermostat that was stuck open. Replacing the t'stat fixed his surge. I haven't done that yet.
I did do the cooling system air purge thing, but that hasn't helped either.
The temp guage sits at about 1/3 up from no temp. Manual says it should be around 1/2.
If the a/c is running, it doesn't surge, only when the a/c is off.
Another thing mentioned was the IAC. Where is that, and how do I check it?
Any other ideas or experience with this? This is driving me crazy, and I won't drive the car until I fix it.
Oh yeah, I attempted to pull the OBD codes. I had a check engine light, and the first code was P0505. I couldn't get the 2nd code. Apparently my son had left the OBD reader outside in the rain, and it started acting weird. I blew it out and dried it, but don't have any codes set right now......
Thanks in advance for any help.... /glenn
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you should break down and buy a $20 Haynes manual,P/N 42025. then you would know where the IAC valve is. Page 6-16. It would also aid in answering most of your other questions.
Of course a Helm's manual is much better,but much more expensive.
any auto store should have the Haynes manual.
--
Jim Yanik
jyanik
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On Saturday, July 23, 2011 9:05:18 PM UTC-4, /g wrote:

Most likely your idle air control valve!
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