RE: CB1100 Idle speed instability problem

Ah, i made another boo boo, with my limited vocabulary ( and copious use of a spellchecker ) i was under the impression that "emeritus" was just a title of merit.
After all comments and corrections i actually googled it and it turns out i was wrong again, had no idea that it involved retirement.:rofl:
So what would be a more fitting title in it's place?
 
'Esteemed'? 'Revered'? 'Eximious'?

I'd go with eximious.

Indeed, we should probably style him the Right Honourable Most Extremely Eximious Lord Popgun.

Or not. :P

Lord Popgun_imp said:
peterbaron_imp said:
Cormanus_imp said:
And you’re apparently Lord Popgun ‘emeritus’. From what have you retired?
Thank you, I was going to ask the same question.... :)
Thank you, I was going to ask the same question.... :)
I’m not getting this. What am I missing?

And no questions about what a FET is?
Alternatives:

1. Field Effect Transistor
2. Future and emerging technologies
3. Further Education and Training
4. Frozen Embroyo Transfer
5. Fluctuating Electronic Thingies
6. Ferret's Endless Trips

The list kinda goes on, really. :D
 
1. is what it is and 5 pretty much describes it’s operation ;)

I’m good with eximious—I had to look it up. Says it archaic but so am I :)
 
Lambchops_imp said:
I reached out to the Japanese forum to ask for further information on the ECU update and was given another link.

Here is a blog post by a staff working at yet another Honda official shop running an update/reset.

Note the Honda MCI tool (Motorcycle communication interface) at the clocks of the bike.

Here is the link with more pictures: https://shop.plaza.rakuten.co.jp/yokorin/diary/detail/201511300000
Any interest from your Japanese friends to remove the ECU governor limiting speed @ 180KPH?
 
If an ECU reset is the root cause, then why does replacing the IACV completely and permanently correct the problem?

Had my bike to the dealer twice, contacted Honda factory directly, and personally spoke to a Factory Honda service representative and was told absolutely each time that there was no ECU remap available from Honda in the USA.
 
Dave_imp said:
If an ECU reset is the root cause, then why does replacing the IACV completely and permanently correct the problem?

Had my bike to the dealer twice, contacted Honda factory directly, and personally spoke to a Factory Honda service representative and was told absolutely each time that there was no ECU remap available from Honda in the USA.
My thoughts, also.
In addition to your success...
Success in post 1162 (page 117) of main thread, by Speed in Barcelona
Success in post 1176 (page 118) of main thread, by Synconizator in Poland

http://cb1100forum.com/forum/showthread....0&page=117

Also, a new or reflashed ECU will not cure a broken TPS wire or TPS issue.

However, a reflashed ECU may handle whatever is going on with the IACV, in some cases, when an ECU reflash is available.

Still do not know if it is a new program or only the original program reinstalled.
 
Had the same question Dave, it seems both repairs work and besides that the bikes are fine when new mostly.
The date of Lambchops's link ( thank you ) shows the date of the post as 2015/11/30 21:08.
So the repairs would have been done some time before that date.

Since the iacv stepper motor has two coils and consequently four wires i wonder what would happen if the wires of one of the coils were swapped over In the harness or connector and the magnetic field would still attract the rotor but in the opposite way....:huh:...
Still a mystery.
 
Thread starter
Dave_imp said:
If an ECU reset is the root cause, then why does replacing the IACV completely and permanently correct the problem?

Had my bike to the dealer twice, contacted Honda factory directly, and personally spoke to a Factory Honda service representative and was told absolutely each time that there was no ECU remap available from Honda in the USA.
An ECU reset is not the cause. Rather it is likely a faulty IACV sending an error to the ECU which then responds erroneously to rectify it. Rather than replace the IACV which solves the problem, the ECU can be rewritten to ignore such errors from an IACV.

In any case it appears that this ECU “update” is a fix that isn’t officially pushed out worldwide. Even in Japan, the dealer will only run this fix for customers who complain specifically about the idle issue. It’s not something that is done to every CB1100 that comes in for a routine service. Therefore it isn’t really an update.

It is unlikely that Honda will put out a fix like this in the USA as it would mean admitting some kind of fault.

When you ask your American Honda representative, most probably they will run a search in their system and see that there isn’t an update available. However if you can push them to check with Honda Japan with proof of pictures they might have a different response. And that’s a big IF.
 
Keep in mind that our IACV does not have a feedback loop. It doesn't send anything to the ECU.
 
Lambchops agree completely with your post except Popgun is right, no feedback is available from the iacv, ( although you could look at the rpm's and call that feedback, just how you interpretate feedback )

What happens is; whenever the bike initiates ( when you hear the fuel pump prime ) the iacv opens completely to the stop, and depending on the engine temp it then closes to supply air to idle the engine at the programmed amount.

It also activates on the clutch lever switch and the throttle and assist to prevent stalling from a standstill as programmed.

You can check this by starting the engine before the pump finishes priming, the rev's are higher and return quickly to the correct setpoint.

What i personally think happens is; the pulses are just long enough to rotate the iacv when new but as the permanent magnets inside the iacv heat up ( slow traffic ) over time they lose strength and the ability to work with the short pulses.
Something changes to deteriorate some iacv's over time and they don't respond well with small steps.
I think the software provides better shaped pulses ( more energy ) as was provided with the old software.
Noticed some half shaped pulses on the owner from spain with his research, starting with a full shaped pulse step is better then a fraction of that value.

We may never know what really happens but this is my best shot at the moment.
 
max_imp said:
Lambchops agree completely with your post except Popgun is right, no feedback is available from the iacv, ( although you could look at the rpm's and call that feedback, just how you interpretate feedback )

What happens is; whenever the bike initiates ( when you hear the fuel pump prime ) the iacv opens completely to the stop, and depending on the engine temp it then closes to supply air to idle the engine at the programmed amount.

It also activates on the clutch lever switch and the throttle and assist to prevent stalling from a standstill as programmed.

You can check this by starting the engine before the pump finishes priming, the rev's are higher and return quickly to the correct setpoint.

What i personally think happens is; the pulses are just long enough to rotate the iacv when new but as the permanent magnets inside the iacv heat up ( slow traffic ) over time they lose strength and the ability to work with the short pulses.
Something changes to deteriorate some iacv's over time and they don't respond well with small steps.
I think the software provides better shaped pulses ( more energy ) as was provided with the old software.
Noticed some half shaped pulses on the owner from spain with his research, starting with a full shaped pulse step is better then a fraction of that value.

We may never know what really happens but this is my best shot at the moment.
VERY logical, Max.
As good an explanation as we may encounter.

If this forum had likes or reputation points, I'd give you a ton.
 
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