Not saying this will resolve your issue but I had the same problem. I ended up replacing parts and checking various things. When I finally brought it to Honda they said I had the fast idle valve too high. It is a screw somewhere under the hood. I'm sure others can explain better. Basically I did not adjust it properly and it caused an idle surge. I could have kicked myself as it was a very simple fix. Just an FYI.

My issue was on a 92 accord lx, 4 cyl.

 

Stonr sounds like it could be an air pocket in the cooling system.

Adstudio & eckhart sounds more like the base idle setting.

The 'Fast' idle is the FIT valve, whichis new in adstudio's car(according to the first post).

Probably what happened to your car was the idle adjust screw in the throttle body was set wrong. You have to set the "BASE" idle speed, which is probably about 500 rpm. Look it up, because it might be different based on year & model.

Find the idle adjust screw above the bore of the throttle body, it's recessed in a hole.

Warm up the engine completely. Turn off all electical loads. Jumper the SCS connector.

Now unplug the IAC valve. The idle will drop low; you might have to use the throttle to keep it from stalling.

Adjust the idle screw to get 500 rpm (or whatever value you find for you year/model). Turn off the car & reset the ECU (disconnect battery). Plug the IACV back in. Remove the jumper from the SCS connector. Let it cool down.

Start the engine without touching the gas pedal. Let it warm up completely without touching the gas pedal.

 

Thanks, I'd like to replace the thermostat anyway. Whats the best/proper way to bleed the system?
I work in a shop, but I sell the jobs and what not, I dont do the actual work. The owners do charge us a low rate, and I hate to ask the tech to help after hours since I think this should be a pretty easy job.
Mitchells shows .8/hr to change the stat.

 

Stoenr (sorry about spleling your name up their)...
What year? What engine? They're all different.

Many years have a little bleed valve at the thermostat housing. You fill up the system & open that bleeder to let out the air bubbles. Mitchell probably shows a picture of that bleeder along with the thermostat instructions.

Hondas don't like air bubbles in the cooling system.

 

94 Accord EX, sorry, Im use to having a signature with info
Im assuming the 2.2L F22B1

I will look into Mitchells, just havent had the time.

 

haha!!
ok, ok...
thanks everyone for the input, I found out what the problem was. I knew it was going to be something stupid since we checked the most common stuff but I didn't think it'd be this dumb...

The previous owner replaced the motor, when swapping the motor he crossed two of the vacuum lines...
After reconnecting them the right way and adjusting idle, everythings good. haha!

All that for something so dumb! had to sit andcompare it withanother accord to find it though.

Thanks again, hopefully this thread helps out someone I know too many people with hondas having this problem.