When checking, cleaning the IAC shouldn't the plunger cycle down into the intake somewhat accompanied with some light clicking sounds when the ignition is turned on. It isn't doing anything. Bike I'm talking about is the one in my sig.

 

No it will close completely and move back to it's parked position when you turn the key off.

 

And when you turn the key on what does it do?

 

IAC is usually a go/no go test. If it moves shortly after you start the bike it works. If not it is either dirty and needs cleaning, or it has failed. Are you experiencing any issues like erratic/ high idle?

 

I'm not seeing any movement when I turn on the ignition. When cold it starts hard and idles, runs rough until it warms up. Once up to temp it runs pretty well. When up to highway speed I still notice an issue when letting off, feathering the throttle in 6th gear. Runs good when accelerating (calling for fuel) up to speed. I have an additional tmax and the stock ecu. I have tried all three and I still can't see the iac move when turning the ignition on. Spayed with carb cleaner and still nothing. I'm thinking that the iac has failed. Do they fail often? Hard to change? Bike has 38,000 miles on it.

 

Should have paid more attention to your reply. You're saying that the iac doesn't move until the motor starts?

 

Actually it will move (I believe out) when you turn it off. Then after a short warm up period it will move the other way. If it is not moving it is toast. Straight forward process, but you need to get a voltage reading off of the TPS prior to removing the IAC so that you can set it to the proper position after the new IAC is installed. .

 

When you turn the key off it goes totally closed and then retracts to it's parked position. That's determined by a "constant" setting and then it has "warmup steps" and "crank to run" steps added. Not all tuning devices give access to these tables, some only to the warmup enrichment tables. All of the tables except the constant setting are temp based and decay over time. A cold parked position may be 120 "steps". The ecm will take control of the steps based on the throttle plate postion to control idle. Usually I will adjust the throttle blade to show 40+/- steps at 105*C. This allows it enough room to move in both directions.