CB1100 Idle speed instability problem

[the Ferret]

Honeymoon? Congrats John!

[dave]

Gone for two weeks on honeymoon and this thread has updated significantly.

Magnus, thanks for all the hard work and details on the tear down. Did you reset the ECU after replacing the IACV?

Dave, sorry to hear about Honda's response. It does sound like you're working with a third party. Any chance you can get the bike to dealer (if you didn't already)? Are you still under warranty? I'll call Kelly and leave my experience with her.

Thanks John, and congratulations! Replacing the IACV on your bike worked, but when Magnus did the same it did not cure the problem. I was actually going to replace my IACV (even though I didn't think this would work but I was willing to try almost anything), but because of Magnus's results I will not pursue this option. Maybe Magnus could contact Honda? My bike is out of warranty. I had my bike inspected by the dealer three different times shortly after purchasing it for a different problem, that I ended up repairing myself with the TPS reset. I have talked to my Honda dealer twice on this topic, getting the exact same answer that I received in my previous post. I have gotten to the point where I am not enjoying riding this bike. If I spend time riding at slow, stop & go speeds it will either go into the low idle/stall phase, or it will go into the high (1,500 RPM) phase. Best wishes to the newlyweds!

[johnf514_imp]

Thank you all for the best wishes. Pretty lucky guy, I got the better end of that deal.

I completely understand not enjoying the bike with the high idle condition. For reference, my IACV was replaced and repaired by Central Florida Powersports service dept, working with Jimmy Le, between 11/4-11/8/2016. If you'd like to reference that with any rep you speak with, they can refer to what the Honda tech discovered on my bike for your issue.

Not to assume the problems are the same, but perhaps if they follow the same diagnostic procedure, we can get an answer.

I appreciate that this might not be a fiscally viable option. In that case, maybe pull the EOT sensor and see if that works? I empathize with you Dave, it is a pain in the rear tire.

[Hatred66_imp]

Hi fellow riders,

After a few months following this thread I've decided to come out of the closet as another CB owner that suffers the unstable idle speed issue. I own a 2014 Std Black, and I am in love with the bike... except for this. Sometimes, specially when it's hot, the bike feels like it's about to die when I'm stopped in a traffic light or stop sign. It gets as low as 500 RPM (literally at that point I don't even feel the engine running). After a few seconds, the idling goes back to 1000 RPM (where it was every single ride for the first year, before this problem started). Other times, for no reason and usually after putting gas or start the bike, the idling gets to 1500 RPM, which almost feels like I am slightly on the throttle non stop. At those 1500 RPM the bike feels over its normal revs, switching gears is not as smooth, there's some pulling while cruising, and probably the gas mileage is lower.

As far as I read there's still not one official diagnosis and fix for this issue, only different attempts with different results done by other riders, dealers or mechanics. So, at this point, where the heck is Honda when a bunch of customers are reporting a malfunction in several bikes that are in good shape? How is it possible that nobody working on the bike including Honda dealers have found the reason that causes this?

Sorry for venting but I am so frustrated!!!! I can't believe I don't rely on a consistent ride I only enjoyed for 1 year after spending 10 grand. I love this bike and I always trusted Japanese quality, but for what I expected from the most classic Honda bike, this has been a bummer so far.

I have to do my 8.000 miles check in a few days, so I'll let you guys know if I get any luck from my Honda dealer. Thanks everyone trying to figure this out! at least I'm not the only one...

[Riko_imp]

When you are at @500 rpm, if blip the throttle, does it actually die??

[Sandhog_imp]

I too am having problems with my bike which is a 2013 ABS model, the low-idle problem occurs whenever I'm riding for 15-20 minutes in heavy stop and go traffic. I've called Honda twice now on the issue and they don't appear aware of the problem. I had one dealer in New Jersey check the bike and they couldn't replicate the issue or find anything wrong, a second dealer I spoke with was not aware of any engine idle issues, a third dealer is looking at the bike now, I hope to hear back from them later this week and will post a follow up. Thanks.

[Lord Popgun]

Sandhog, they know. Read Dave's post above: http://cb1100forum.com/forum/showthread....#pid166901

Good luck with the 3rd dealer, but I wouldn't expect much. Unless its a hard failure, we seem to be on our own in the US. Mine is OK, but I have been following this since it was first reported here and would like to see a resolution.

[johnf514_imp]

Just a quick note for the newcomers to this thread. While I am only one case, I also had low RPM idle issues and stalling when driving in heavy stop n go traffic, and I had the high idle condition, which was temporarily resolved twice with ECU resets. The third time, the dealership replaced the IACV under warranty, and the bike has not exhibited low/high idle RPM conditions since.

I appreciate that I am only one case, just wanted to summarize and share.

[Ben70_imp]

From my experience in the automotive world, it was (and is), common for some multi-port fuel injected vehicles to be plagued with a carbon sludge deposit that forms around the throttle plate. This would cause uneven or low idle, sometimes dying, and a hesitation on acceleration in some cases.
I am pretty sure that this would usually only happen with an average higher mileage than most of us have on our bikes.
The fix was to open the throttle and clean around the bore where the throttle closes, and the back (inner) side of the throttle plate. The most sparkly clean results come from pulling the throttle body for thorough cleaning, but i had good luck with a toothbrush and some Berryman's Chemtool.
If I were plagued with this issue, I would try to access the throttle bores so I could assess the possible accumulation by opening the throttle and wiping a q-tip around the area where the throttle plate closes, if it comes out clean, that's not the problem.

Ben

[Hatred66_imp]

When you are at @500 rpm, if blip the throttle, does it actually die??

Hey Riko,

Mine has never died while I'm stopped, although sometimes I literally felt like the engine was off due to total lack of sound/vibration. Usually after some seconds in that 500 RPM quiet idling, the bike goes back to 1000 RPM where it behaves "normal". The problem is that sometimes the light goes green and you don't have that extra time. In those cases the bike doesn't take off as easily since I have to apply extra throttle to compensate the low idling. If I don't do so the bike will die (again, due to starting on 1st gear with lower RPM than normal). Annoying and weird!
With the high idling, there is no variation. If the ride starts at 1500 RPM and never goes down to 1000 RPM, it will stay like that the entire ride, regardless of full stops, highway, temperature, etc.

All this is what makes the bike unpredictable...