I reported that my high/low idle problem was cured by a WFO run about 2 months and 2,500 miles ago. Well, it's back. It ran good as new for about 2,500 miles, and then began hinting of the fast idle last week when it took longer than normal to return to the "normal" 1050 RPM idle during a ride around town. Took the wife for a ride downtown to view all the "interesting" folks visiting our town for the Comic con event Saturday evening and as expected, we got stuck in the traffic. I knew this would be a good excuse to "stress test" my bike anyway. Despite the warmer-than-normal temperature, the slow speeds (when we were moving), and the extended waits at the red lights, my idle was perfect, for the first 20 minutes (probably 15 minutes of not moving at all). After not moving for almost 5 minutes at one stop I turned the engine off. When I turned it back on it was idling at 1,500 RPM. I continued to turn the engine off at the red lights for the next 10 minutes or so, but it was idling at 1,500, and even went as high as 1,700 at one point (it has never done this before). We then drove at an easy 65 mph on the freeway for about 6 - 8 miles, hoping that cooling the engine off would do something, but it didn't. We then stopped for an ice cream, so the bike sat for about 30 minutes. When I restarted it the idle returned to 1,050 RPM, and remained this way for the ride home, with about 3 or 4 stop lights. Riding the bike the next day the idle speed was 1,050 RPM. I will ride it tonight and see what happens.
CB1100 Idle speed instability problem
- Thread starter ericlo69_imp
- Start date
johnf514_imp
Running like a top
Dave, that behavior sounds very similar to how my high idle condition came about. Turning off the engine after being idled in traffic at a light, I fired it back up and had 1500 RPM idle. Occasionally it would return to 1050 RPM idle, but it would default to 1500 after a few rides.
Let us know how it all goes. You may have to for another WFO. What a shame.
Let us know how it all goes. You may have to for another WFO. What a shame.
So I took the bike when I went to dinner last night. About 5 miles of freeway, and three red lights (each way). The engine had plenty of time to reach operating temperature, but the idle was a perfect 1,050 RPM. This problem sure has me challenged! I'm thinking that maybe something in the way the IACV works is causing it to stick, and not function properly. Does anyone out there understand what controls the input to the IACV, and maybe how it functions? I am convinced that the engine operating temperature has something to do with it because when I unplug the Engine Oil Temperature (EOT) sensor when the idle goes to 1,500 RPM the engine returns to 1,050 RPM. Maybe the EOT sensor is sending a wrong signal to the ECU telling it that the engine is cold and therefore adjust the IACV to increase the idle speed? But I replaced the EOT sensor and this did not fix the problem. I'd replace the IACV, but another member reported that he did this and it did not correct the problem. I'm going to take it out to the desert and make another WFO run to see if this works again, as soon as I get a chance.
I think my problem started around 8k miles also.johnf514_imp said:
the Ferret
Road warrior
On our recent Colorado trip, there was an accident that had the freeway shut down, so we exited looking for an alternate route as did thousands of others. The result was a log jam. Round abouts in the city we exited in were just locked up, and even though we could maneuver faster than cars, and could switch lanes faster to try and keep moving,we were in stop and go traffic that was mostly stopped for about and hour and two miles. All 3 2014 CB's (2 dlx 1 std) were getting seriously hot so we turned them off, and restarted them often, before we finally broke thru traffic. No idle issues on any of them. I think both LR and Offroad have about 6 or 7,000 miles on theirs and I have over 34,000 on mine. So I am not sure it's stop and go traffic and a few lights causing this, but it does seem to be a common denominator in most of the issues we are reading about. Baffling and maddening.
Wisedrum
Road warrior
The often restarts may be the reason for your CB and the ones of your buddies, that they don't fell into this strange idle thing. Only a presumption, because we are still in the land of theories and confusion, when it comes to the curation of it. But maybe your Hondas will never fall into it, no matter where they drive and how they been ridden.The ferret_imp said:
My CB is/ was a candidate for it, I can't say it for sure which time form is the case now. Since a few weeks it idles well again after longer periods on the higher side.
But I have in mind that the trouble can start again, in a way comes and goes like the Honda finds it appropriate.
Me and my bike live with it as long as no other malefunction adds to this one, which hinders it from keep on running.
Wisedrum
Lord Popgun
Road warrior
Dave, For some time I've been wondering for some time if maybe the IACV needle is maybe hanging up. Maybe in its seat. Maybe that's why Rico's bike was fixed when they changed the whole throttle body.
But, I'm not taking my bike apart to investigate this unless I have the problem.
The IACV is driven by the ECU. I can imagine any of the inputs to the ECU could/would affect the idle. I wish we had more info or at least a common cause.
But, I'm not taking my bike apart to investigate this unless I have the problem.
The IACV is driven by the ECU. I can imagine any of the inputs to the ECU could/would affect the idle. I wish we had more info or at least a common cause.
'tis baffling...mine was just the opposite...no traffic, no stops, just 1 hour of 40-60mph country riding. Then turned off for gas, started it and 1500rpm and wouldn't budge from there till bike cooled.The ferret_imp said:
johnf514_imp
Running like a top
pdedse, are you saying the high idle condition went away after the bike cooled down and was restarted?
Yes, about an hour later I started the bike and it held steady at 1000 or maybe it was 1050rpm, but I didn't ride it more. That was about 10,11 days ago but then I left for vacation and I still have another week before I return home.johnf514_imp said:
I'll get it out again a week from this Saturday to see what it does.
johnf514_imp
Running like a top
What a fickle gremlin, this high idle.pdedse_imp said:
What a fickle gremlin, this high idle.johnf514_imp said:
Now it has character! : )
the Ferret
Road warrior
What a fickle gremlin, this high idle.pdedse_imp said:
Now it has character! : )
[/QUOTE]
:rofl:
Magnus_imp
First service completed
I'm having pretty much the same problem as you as I previously posted. While the high idle seemed pretty constant for a while now it seems to come and go at will. I've kinda thrown in the towel and I'm just trying to ignore it now when it happens. Replacing the IACV was a bit of an involved job and made no difference. I replaced the EOT sensor as well.Dave_imp said:
Vey's Powersports in San Diego (El Cajon) has a new 2014 CB1100 for $5999 - maybe I should just buy a new one!
I'm having pretty much the same problem as you as I previously posted. While the high idle seemed pretty constant for a while now it seems to come and go at will. I've kinda thrown in the towel and I'm just trying to ignore it now when it happens. Replacing the IACV was a bit of an involved job and made no difference. I replaced the EOT sensor as well.
Magnus, did you closely inspect the operation of the IACV before completing your reassembly? Is it possible the IACVs on the affected bikes are just sticking? I don't understand exactly how the IACV works. I listen carefully for it every time I turn my ignition key on and I hear it cycling. Can it make this noise that sounds like it's working but in reality it's sticking? What kind of movement of the IACV are we talking about - a few thousands of an inch, or a few tenths? I'm wondering how sensitive it is. If its total movement is only a few thousandths of an inch then maybe some slight sticking is the root cause? Does fuel run over this valve, or is it just air only? I am wondering if adding fuel injection cleaner could help (actually I have already tried this - unsuccessfully).
Magnus, did you closely inspect the operation of the IACV before completing your reassembly? Is it possible the IACVs on the affected bikes are just sticking? I don't understand exactly how the IACV works. I listen carefully for it every time I turn my ignition key on and I hear it cycling. Can it make this noise that sounds like it's working but in reality it's sticking? What kind of movement of the IACV are we talking about - a few thousands of an inch, or a few tenths? I'm wondering how sensitive it is. If its total movement is only a few thousandths of an inch then maybe some slight sticking is the root cause? Does fuel run over this valve, or is it just air only? I am wondering if adding fuel injection cleaner could help (actually I have already tried this - unsuccessfully).
I've held off posting back to this thread more than I'd originally intended to but here is the current state of my issue. As previously posted I did the throttle twist reset and it 'cured' the high idle...till about the middle of the next day. I didn't ride for a day after that and then I did the reset one more time. The bike has idled perfectly every day since. At this point I've run about half of my bottle of Lucas injector cleaner through it and I'll finish the bottle. I don't know if it did anything. The only real, immediately observable and positive effect resulted from the throttle reset.
My riding style is pretty sedate. I never speed on the bike. Since I quit commuting on it two seasons ago I probably haven't exceeded 50 mph on it. The throttle has never been worked stop to stop. Is it possible that this somehow messes with the computer? If that is in any way possible, every ride now gets at least one full throttle roll on. Maybe that will help the system to remember where 0 is and where 100 is and maybe that will help it to know where the correct idle point is. Or not.
My riding style is pretty sedate. I never speed on the bike. Since I quit commuting on it two seasons ago I probably haven't exceeded 50 mph on it. The throttle has never been worked stop to stop. Is it possible that this somehow messes with the computer? If that is in any way possible, every ride now gets at least one full throttle roll on. Maybe that will help the system to remember where 0 is and where 100 is and maybe that will help it to know where the correct idle point is. Or not.
So for those with high idle issues...frustrating as it may be, are there any long term problems with just ignoring it, ride like you always do and just live with it? Anyone with high idle have stalling issues? I actually bought this bike to do long distance rides, travel the Northwest lots and across the US a couple of times.
My idle issues initially started with low RPM and stalling. Every now and again the idle will dip down to about 500 RPM when I put it in neutral at a stoplight, but it has been returning back to 1,050 RPM by itself. Concerning the "just live with it" approach: I HATE slamming my bike into first gear from neutral at every stoplight when it is idling at 1,500 RPM - this makes me feel like I'm riding a Harley! This can't be helping the transmission.pdedse_imp said:
Lord Popgun
Road warrior
Dave, the IACV is two parts. A stepper motor connected to a slide valve (service manual term, not mine). The ECU commands the stepper motor and it rotates the slide valve.
I don't know how much it rotates. The manual says when installing, turn the slide valve clockwise until lightly seated on the IACV. The arrow showing rotation on the picture could be construed as showing around 90 degrees, but no value is listed and I do not know.
The throttle valves and IACV are upstream from the injectors. They control air. The ECU controls fuel by varying the injector dwell time bases on the TPS position and other inputs, fuel map and all that.
You can see this if you go look at your engine. The injectors are the last this before the throttle body rubber mount to the cylinder head. Cars are pretty much the same way.
I don't know how much it rotates. The manual says when installing, turn the slide valve clockwise until lightly seated on the IACV. The arrow showing rotation on the picture could be construed as showing around 90 degrees, but no value is listed and I do not know.
The throttle valves and IACV are upstream from the injectors. They control air. The ECU controls fuel by varying the injector dwell time bases on the TPS position and other inputs, fuel map and all that.
You can see this if you go look at your engine. The injectors are the last this before the throttle body rubber mount to the cylinder head. Cars are pretty much the same way.
postoak_imp
Been there
So this happens on the 2013s, 2014s, and (where available) the 2015s?
Does it happen on those bikes that have had the ECU mod done by Guhl?
Does it happen on those bikes that have had the ECU mod done by Guhl?
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