CB1100 Idle speed instability problem

[Lord Popgun]

Yes, same part

[beardyweirdy@me.com_imp]

I get a low MPG of 30-33 on my daily commute, have since 2014. In less stop & go it goes into the 50's. Beardy if you want to have beer together in Seattle let me know. Jonz

Thanks Jonz,

If our shaky schedule makes it to Seattle... I'll keep you posted.
I'll no doubt need a beer or two by then.
With regard to the MPG, to be fair, I do have a PCv that needs a tune. It was set up when I didn't have the bike sorted and it could be running rich.

Once I'm back I'll get it on the Dyno and have it tuned. Hopefully that with sort it out.

It's also geared lower, had the ECU/ECM ;-) flashed and has a free flowing air box, pipe and bigger throttle body inlets.... I'll report back when it's tuned.

[ericlo69_imp]

Update:
Here in Taiwan, recently HONDA released new (revised) ECU program to solve CB1100 idle speed problem; some owners start to send their bikes to dealer side for new ECU program uploading. (BUT there is not RECALL from HONDA Taiwan dealers). One owner mentioned that his bike (EX model, Throttle body assy has been replaced before because of idle speed unstable) is getting smoother and more powerful after uploading.
Just for your reference, and I will keep it updated.

[the Ferret]

Good deal, thanks for the update erico.

[dave]

I've been in contact with the dealer I purchased my bike from. I forwarded them the link to this site, and they we supposed to contact the factory for direction. Here's their latest reply to me:

"As far as California goes, they have yet to release anything to fix that issue. Unfortunately we cannot do anything emissions related that would put the bike out of state compliancy. If we do it would be a $10,000 fine on us so at this point we cannot do anything unless Honda releases a bulletin or recall that meets State and Federal Compliance."

Guess I'll have to contact the factory directly.

[dave]

Sent a certified letter to American Honda today concerning the unstable idle problem. I'll post an update as soon as I receive a reply. Does anyone want to bet me their reply won't be "take it to the dealer and have them look at it"?

[Cormanus]

LOL. No.

[Magnus_imp]

Well... spent the better part of today replacing my Idle Air Control Valve (IACV). To get to it you basically have to take the bike apart from the tail up to the throttle body (Rear fenders, battery, air filter housing, air box). The issue I was hoping it would fix was that my bike always wants to idle high at 1500rpm even when warm. During low speed riding it wants to surge ahead - basically it acts like it always has some throttle applied. I was hoping replacing the IACV would fix this but unfortunately it did not. After a couple minutes of riding the idle actually seemed alright but then a few minutes later back to 1500rpms. Oh well. Any idea?

[Ben70_imp]

Hey, Magnus! Unplugging the EOT sensor dropped the idle for somebody earlier in this thread, implying a possible bad sensor. This is assuming the bike is programmed to idle up under hot oil temp situations, presumably to increase flow thru the oil cooler. Perhaps the EOT sensor could be ohmed, but it would be nice to have some parameters. Good luck.

Ben

[Lord Popgun]

There is a procedure in the service manual for checking the EOT sensor.