Ok I had to add input here I have been fighting a surging idle for 2 months on a car I get to work on about 4-5 hours a week. I am a very busy person so I do not have the luxury to take even a Saturday or Sunday to set aside.
I would like to point out before we get started. I had no CEL this whole time.
First things to check as mentioned above. Burp the coolant system as bubbles in the system especially the IACV aka EACV (Idle Air Control Valve) and ECT (Engine Coolant Temp Sensor) will cause the improper Thermo readings and adjust idle and fuel incorrectly.
My Findings.
1.My vehicle would Idle fine until the engine hit 118F then my wide band would go from stoich and slowly run leaner and leaner the warmer it got, this of course raises RPM until the engine can no longer make power and idle drops. At the point the vacuum would cause the stock Honda fuel table to dump fuel at low RPM causing a buildup of fuel trying to raise the idle. This load of fuel of course fed the engine to speed up and burn the fuel... Hench Surging Idle! And repeat.
At first I checked all vac lines and replaced everyone! Still the problem persisted.
To Google!
clean IACV and FITV... Check, reassemble. Still the problem persisted.
Replace all gaskets on intake manifold to rule out vac leak.... You guessed it. still surging idle.
Pulled the plug on the IACV with the key in the on position engine not running. silence. I did not hear a Click. This car sat for 2+ years and when I put it back together the IACV was humming like it was locked up. :doh: Should have triggered a light bulb above my head there! But I had forgotten about it because it was months ago. It was quiet now.
Tested the IACV plug for voltage 11.6volts dc... I have power! must be the IACV is bad. So I built a test fixture and connected the IACV to my battery 12vt source. CLICK! OMG it works it must be the connector!... NOT!
Swapped the connector to no avail. Searched the Service manual looking at the trouble shooting. Nothing gave me a value to took at.
Dusted off my Snap-on Vantage 2400 (Which is a tool everyone should have if they can afford it. Picked mine up on eBay for $300)
It actually had an expected resistance value of the IACV motor! As well as duty cycle tests and expected voltage tests.
So how did I suspect the IACV? I used my finger. When the Idle was surging all over I took my finger and blocked the top port in the throttle body. This is the bypass hole for the IACV. By doing this I simulated the ECU sent 12vts to the IACV and closed the "air leak" or bypassed air.
This was not in the Honda Service manual:
IACV should read around 20 Ohms across the connector:
IACV should have 10-12Vtc DC sent to it with the key on engine running at operating regular Temp:
IACV should have 6-10Vts DC with lights and fans and blower motor/AC on in the vehicle:
Check for Continuity from each pin to ground. This means the motor is shorted internally:
My results.
Voltage is OK in all checks.

Phew good ECU!
Ohm readings! 39.5 Ohms! :evil:
So some may not realize whats going on.
10-12vts the IACV motor closes and cuts off the bypassed Air.
When the car is first cold started extra fuel is dumped into the engine to warm it up causing a higher than normal idle normally 150-300 RPM. At this point the IACV is opened more to allow the fuel to burn but you are running rich. As the ECT warms up the fuel is slowly cut back and the IACV should close up slowly. It opens when accessory such as lights AC fans blower motor and other accessories are run... to boost the idle.
But wait, yes I did say that the IACV opened when connected to a battery. Without going into Ohms law I will explain that the 12vt signal coming from the ECU is weaker than the 12vt signal directly from the battery. You have a higher amperage direct source from the battery. This meaning that when I use battery juice the battery can work harder to force the 12vts into the IACV where the ECU is limited. Ohms law basically states if you run voltage through resistance on the other side of the resistor the voltage will be lower than what is was originally before the voltage hit the resistance in the circuit. Basically to reach the IACV with double the expected resistance I would need double the 12vt signal at 24vts at the same current reading from the ECU for the IACV to function.
So I hope these values will help someone in the future as again they are not listed in the Service manual. At least the IACV Ohm value is not.
So now that I may have helped can anyone tell me what IACV is the same size as a B16A? The bolt patterns are different. I have to hit the junkyard unless someone here has one.