CB1100 Idle speed instability problem

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2 x pm sent
 
Pb,

That is a chassis ground on pins A23 and A24. They go to Popgun 1 and Popgun 2. The ground is supposed to inhibit snarky posts like this one. Doesn't work, as you can see... :D
 
Hi everyone it's me again back to share my experience with the idle instability issues after 3 years.

I posted in 2020 about findings in Japan that dealt with the idle issues via a ECU update here: CB1100 idle speed instability repair advice

It seemed like the general consensus then was that it is an IACV issue and not ECU. But lately, from what i've read it sounds like the ECU update patch has been shared with EU and has worked. Also, it appears that the older ECU part numbers have been superseded with a newer part number.

I have replaced my IACV twice and still encountered the same issues so I believe it it might be solved with either an ECU update or a new ECU.

DDUMZI has shared his experience here with his ECU: http://cb1100forum.com/forum/showthread....035&page=7

I'll update again if an ECU replacement solves the issue. Wish me luck :)
 
Oh man, its really tough.

OK, not really :) Its under the tank. Basically, remove tank and then just unplug it and remove it from its holder. There are pictures of it on the site somewhere. Unless someone posts a more detailed answer, I’ll search for them later.
 
louied_imp said:
How difficult is ECU replacement? Does anyone have a set of procedures?
It is easy, but takes patience and time. Read all of this first.

1) Empty your fuel tank. The lighter it is, the easier this will be. Remove the fuel tank. This is the hardest part. The fuel lines are connected with a green and black rubber connectors, seen here after disconnected:

The green part is inside the metal fuel line. The black part slides back and forth to hold the green part inside the tube.
In this diagram, number 11 is the green and number 3 is the black piece
You have to disconnect these to get the tank off the bike. Remove the bolt at the rear of the tank and lift it as high as you can. It will only go up an inch or two and that is why it is hard to do. You have to get into that space to disconnect these connections. Most of us prop the tank up with a piece of wood or rolled up towels. I found some old, hard sponges that worked good. It is easier with small, hard, tough hands. You will want some kind of light to see in there because it is dark and these are small pieces. Putting it back together is no easier.
As Popgun said, once the tank is out of the way it is just plug and play. Unplug and discard the old one and plug in the new one. Probably should remove one of the leads from your battery first, too.
My bike is a 2013 standard, so yours may be different if it is another year, but the connectors are probably the same. I threw away what was probably a good IACV yesterday. It was the one I replaced before realizing that it wasn't the problem. Good luck.
 
Thanks Nacho! I didn’t have the time this morning for the whole procedure. Plus, you have nice pics.

There is a change in the quick disconnects, but I forget what year the change was made. Maybe in ‘17. There are procedures in the How to section.
 
Lord Popgun_imp said:
Thanks Nacho! I didn’t have the time this morning for the whole procedure. Plus, you have nice pics.

There is a change in the quick disconnects, but I forget what year the change was made. Maybe in ‘17. There are procedures in the How to section.
:thumbsup::beerchug:
 
Well well well; hello everyone! I have good news (at least in my case). Like many others, I was having idle problems and bike shutting off when stopped at a light or while riding. After reading all the discussions here, I decided to change the iacv myself without ant troubleshooting(I know its crazy but didnt want yo spend hours troubleshooting). So I boight the part and with the help Ingot my hands on a service manual. So I took apart the seat, tank, left and right covers; the rear air filter housing and for the life of me, I couldnot remove front air filter housing that is attached to throttle control. In the effort to do all these, I had disconnected the battery and most harnesses including the computer. So I decided to put everything back and accept defete and take the bike to a shop for repairs. I put everything back and to my surprise the bike was fixed by just disconnecting all the parts and letting it sit for a few days... guys; if you have the same issue; try this; it may help!
 
Cbman_imp said:
Well well well; hello everyone! I have good news (at least in my case). Like many others, I was having idle problems and bike shutting off when stopped at a light or while riding. After reading all the discussions here, I decided to change the iacv myself without ant troubleshooting(I know its crazy but didnt want yo spend hours troubleshooting). So I boight the part and with the help Ingot my hands on a service manual. So I took apart the seat, tank, left and right covers; the rear air filter housing and for the life of me, I couldnot remove front air filter housing that is attached to throttle control. In the effort to do all these, I had disconnected the battery and most harnesses including the computer. So I decided to put everything back and accept defete and take the bike to a shop for repairs. I put everything back and to my surprise the bike was fixed by just disconnecting all the parts and letting it sit for a few days... guys; if you have the same issue; try this; it may help!
Cbman, the IACV is not the problem. It is a lot easier to install a new ECU and solve the problem once and forever. My 2013 ran okay for a week or so after I got the new IACV, but then the problem returned. Only when I put in the new ECU did it idle like a new bike. I hope your problem is resolved, but, if it returns, get a new ECU. The intake air control valve (IACV) probably is not your problem. Good luck with this.
 
I am amazed that after over eleven years, and dozens of owners experiencing this exact same problem, that Honda hasn't figured out the root cause. I replaced my IACV eight years ago and never experienced the problem again. However, there are forum members who have replaced their IACV and this did not solve the problem for them. Some forum members report that ECU replacement is the only solution, and some forum members from Europe have reported that an ECU reflash cured the problem for them. Honda America will not reflash an ECU. The fact that Honda doesn't even acknowledge the problem doesn't speak well for them.
Cbman. Report back to us in a month and tell us if your idle issue has been permanently fixed. My bet is it isn't, but good luck.
 
It is worth mentioning that the ECU I bought from Partzilla had a different part number. No one listed the ECU with the original part number for the 2013. Problem is that wasn't the only year with the problem, so I don't know what happened. I know one of our members in South Korea took his to his Honda shop and they solved his fast idle problem by replacing the ECU. That is why I replaced my ECU.
 
From the 'Old' Forum yesterday:

Fabrimtb said:
Hi guys,I live in Europe, my CB1100 is a 2013 model with ABS. After suffered the problems related to the idle instability, today my bike has been updated with the last version of the ECU software, ECUID 0101390102. I hope this can help you.
 
Hi guys, as I wrote in the "old forum', one month ago after read on the web that in Germany an ECU update is available, I asked about it to the local Honda dealer. Officially there is no info about it, on my request the technician connected the PC to the ECU. He found an available update, but at the same time he meet an error on the TPS, he tried to reset it without any result. After did the update, he was able to do the reset. Since then, I did more than 400 Kms, it seems the bike is ok. I hope it will last and help you.
 
fabrimtb said:
Hi guys, as I wrote in the "old forum', one month ago after read on the web that in Germany an ECU update is available, I asked about it to the local Honda dealer. Officially there is no info about it, on my request the technician connected the PC to the ECU. He found an available update, but at the same time he meet an error on the TPS, he tried to reset it without any result. After did the update, he was able to do the reset. Since then, I did more than 400 Kms, it seems the bike is ok. I hope it will last and help you.

That is an interesting development.  Had this been U.S. available back in 2017, I would likely still have my '14 standard.  But I can't complain with the second go-around on the EX '17.
 
Cbman_imp said:
Well well well; hello everyone! I have good news (at least in my case).  Like many others, I was having idle problems and bike shutting off when stopped at a light or while riding.  After reading all the discussions here, I decided to change the iacv myself without ant troubleshooting(I know its crazy but didnt want yo spend hours troubleshooting). So I boight the part and with the help Ingot my hands on a service manual.  So I took apart the seat, tank, left and right covers; the rear air filter housing and for the life of me, I couldnot remove front air filter housing that is attached to throttle control. In the effort to do all these, I had disconnected the battery and most harnesses including the computer.  So I decided to put everything back and accept defete and take the bike to a shop for repairs.  I put everything back
and to my surprise the bike was fixed by just disconnecting all the parts and letting it sit for a few days... guys; if you have the same issue; try this; it may help!

By disconnecting the battery/ECU for an extended period, you inadvertenly reset all the resudial values in the ECU, but is almost certain that the problem will return ???...
 
It looks to me like Cbman has not moved over to the new forum, so I suspect you'll not get an answer, Dave. You could try sending him a PM or email through the old Forum; sending one from here won't reach him.
 
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