Idle Air Control Valve (IACV)

[dave]

Hi all. I am asking for some feedback from as many members as possible, please. My 2014 Dlx suffers from an intermittent fast (1,500 RPM) to slow (500 RPM/stalling) idle condition. This condition has been discussed by multiple members of this forum and I am seeking some feedback to help in my diagnosis. I suspect the Idle Air Control Valve (IACV) is the root cause of my problem, but I am not convinced. The Honda service manual describes a quick and easy test that I am asking members to perform, and to then post their results. My bike has never passed this test (described below), but whether it passes or not it may or may not run perfectly (right now it is running perfectly). Here's the test: With the engine stop switch (on RH handlebar) in the on position, turn the ignition key on while listening for the IACV step motor to cycle. The IACV is located on the RH side of the bike, between the outer-most throttle body and the cylinder. Can you please perform this test and let me know if you can hear a step motor cycling momentarily? I have never heard a sound (the service manual says I should), but most of the time my bike runs perfectly regardless. Your feedback is appreciated. Thank you.

[Ulvetanna_imp]

my bike has always made this sound

all my bikes make this sound as they are all EFI

no sound means there is a problem

fuel pump may or may not come on but that is a different sound

[Lord Popgun]

I just did the test. You have to put your ear pretty close to the Throttle body on the right side of the engine. Turn on the switch and you will hear the fuel pump (or usually hear it as Ulvetana said) and hear the IACV. It makes a kinda fast clicking sound, but only for maybe a second. Maybe less that a second.

I did the test in my garage with no background noise. The clicking or racheting sound wasn't very loud.

[emptysea]

Turned the ignition key with the engine cutoff switch OFF...no sound whatsoever. Flipped cutoff switch to ON and heard the clicking sound which popgun describes along with the fuel pump.

Went back to my service manual and the test requires the cutoff switch to be ON not OFF as you describe in your original post.

[Lord Popgun]

ES, Actually that is how I did it. Was easier to reach the cutoff switch than the key while my head was by the throttle body

[dave]

Thank you all for your replies. I was wrong, the on/off switch should be in the "ON" position - I'll go back and check mine. I'll get back and let you know if I hear a clicking sound. Please keep the replies coming.

[dsinned_imp]

With cutoff switch "off", mine make no sound whatsoever as I turn "on" the ignition key switch. But when I toggle the cutoff SW to "on", I DO hear the sound of the fuel pump priming the system. I'm not sure if there is suppose to be another sound coming from the IACV at the same time, but I don't think so.

[Lord Popgun]

There is. It cycles as part of the ignition on secquence. It in the service manual.

[dsinned_imp]

. . . details, details, DETAILS.

Okay, I repeated the test, this time with the ignition key SW already On, then turning On the cutoff SW with my ear close to the RHS. Now, I can hear a faint ticking sound for about a second coming from the IACV, AND at the same time, the other sound of the fuel pump priming the system for a few seconds longer.

[Lord Popgun]

There ya go!