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+--- Thread: IACV Replacement Tips (/showthread.php?tid=5069)
RE: IACV Replacement Tips - max - 11-09-2018
Any bit of wire will do the job as long as it can be inserted comfortably within the time limit, the dealer one uses a small switch i think but the size of the wire and the way it folded up was just convenient for me.
Playing with electronics i always have too many bits laying around and this one was nice in the way it folded making it easy to get in and out of the connector without splaying the pins open, automotive connectors are getting smaller, lighter and better in water resistance but a bit more fragile than spade or old fashioned bullit connectors.
And well done for pointing this out, it is probably a bit safer to use a resistor just in case the orange wire which carries 12 volts gets connected to the green earth wire by mistake but of course not every body have some resistors handy.
RE: IACV Replacement Tips - snackie_imp - 11-11-2018
Thanks everyone for your time and input.
So far, I have shorted the DLC by connecting the Brown and Green wires with a resistor. If I did it correctly, there were no stored codes. But, just to be sure, I have ordered the SCS connector.
I also warmed up the bike (without touching the throttle as this will increase the idle speed) then shut down the bike and removed the plug from the IACV motor. When I restarted the bike, it maintained a normal idle while pulling on the throttle. As soon as I reattached the plug to the IACV the idle shot back up to 1500 rpms.
Do you think it is safe to assume that the IACV motor is the culprit at this point or should I do further testing?
Thanks.
RE: IACV Replacement Tips - max - 11-11-2018
Sure looks like it Brian, apart from one member who found a twisted pin in the tps connector, had the same or similar idle issue and corrected it by looking at it very closely and then correctly re-inserted the pin in the connector, that may be worth a look in your case because it is easy to do, just make sure your tps cable is long enough so the connector does not get stressed when it is unplugged, you may have to take off the left tb plastic cover off to ease the cable out a bit.
all other cases have been solved by replacing the iacv, i do find it odd that the idle increased when the iacv was re connected, you observed something that we have not heard of before.
And like i mentioned before we don't know why the iacv misbehaves, it does not appear to be stuck or dirty, all we know is that if it is replaced the mysterious effect goes away and we have tried numerous things that could have had an influence on the idle rpm, none fixed it and replacing the iacv did!
The first confirmed case was Riko from Belgium, he had his entire throttle body replaced which is the recommended Honda cure and it did solve it completely, there were only two electrical parts on the tb, the tps and the iacv, so we eliminated the tps and the only thing left was the iacv to make a long story short.
It seems you are the type of guy that can handle this kind of job, it might be an idea to take some key pictures and do a brief description of what is involved so others can use this in the future.
Aloha and thanks for the precise feedback.
RE: IACV Replacement Tips - snackie_imp - 11-12-2018
Max,
The idle shot back up after I reattached the plug to the IACV and then pulled the throttle. What I have experienced is an increase in the idle speed AFTER the bike has warmed up and you pull the throttle. If you just start the bike and let it warm up, it will idle fine but as soon as you give it gas the idle begins to increase.
RE: IACV Replacement Tips - max - 11-12-2018
I'm glad you told me this Bryan, that makes a lot more sense, from your first account it seemed like an iacv setting was stored in memory and was executed right when it was connected, i can discard that idea now.
The iacv is doing a lot of work, every time the throttle is moved the iacv moves a few steps ( it's a stepper motor with two sets of windings and around 128 steps ) and stays in the last idle position when the ignition is switched off, it resets every time the bike is switched on and moves to it's startup position depending on the engine temperature, with the great help from popgun we figured out how this process works, the same iacv is used a lot on Honda's and sometimes fails.
Here is a video ( which did not upload as it should have but showing what roughly happens when it operates, again this one does not have the idle problem;
https://www.youtube.com/watch?v=MFA5Mk4vS3c
Thanks for the correction.
RE: IACV Replacement Tips - dave - 11-12-2018
Hi Snackie. I was one of three or four forum members who have replaced their IACV. It looks like the guys have all got you started down the correct path, so I won't offer any additional advice except to comment that there are a GREAT bunch of very talented people on this forum who will help you (including me) if you any questions.
RE: IACV Replacement Tips - snackie_imp - 11-12-2018
Hi Dave,
Just wondering if my description of the problem is similar to what you experienced? How many miles did you have on your bike when the problem occurred and how many miles have you put on the bike since you replaced the IACV?
Thank you!
RE: IACV Replacement Tips - snackie_imp - 11-14-2018
UPDATE:
I bypassed the IACV (unplugged the motor) and it idles and runs fine. Think I'll do this until I get around to fixing it but I'm wondering what, if any, implications there may be. Any thoughts?
Thanks,
Snackie
RE: IACV Replacement Tips - max - 11-14-2018
I'm glad you did Bryan, other than the cel it should be ok ( anybody else ? ).
What you have here is nothing other than the equivalent of a manual idle adjustment screw and it should not change the behavior of the bike which would be some variation of " limp mode ".
Depending on which model and year unplugging of the tps caused the engine to have a " softer " character, it is very subtle but noticeable but i don't think unplugging the iacv has any influence on engine behavior, it will only warn you through the cel, if that bothers you, it may be that putting resistors ( 1 k ohm ) in place of the two coils will make the ecm happy again, worth a try in the longer run.
Thanks for the update, knowledge gained
RE: IACV Replacement Tips - snackie_imp - 11-14-2018
Yep, I definitely noticed a more mild mannered motorcycle, but works for me in the short term.