CB1100 Idle speed instability problem

[max]

Also thinking about using a "one shot" configuration ( google it ), that is an ic that produces a pulse for a set time independent of the input pulse, so if the input pulse is too short this gizmo will change that to a normal with pulse which should solve this problem and do this for both channels with the likes of a 556 or a 4098 ic, looking at a plug-and-play option......

[pdedse]

Also thinking about using a "one shot" configuration ( google it ), that is an ic that produces a pulse for a set time independent of the input pulse, so if the input pulse is too short this gizmo will change that to a normal with pulse which should solve this problem and do this for both channels with the likes of a 556 or a 4098 ic, looking at a plug-and-play option......

So what are we talking about... Electric Shock Therapy?

[iamheero_imp]

Hey guys, so I wanted to update, I've unplugged the IACV and have uploaded a video showing how I did so following Max's advice. I waited for the bike to warm up, key off, iacv unplugged. Tomorrow I'll be going on a ride to see if there are any issues. It's funny, in filming the video I had to leave the apartment garage to get some light and while pulling out the bike, the idle was at like 1800rpm and wouldn't go down at all until I kill-switch-reset the bike. Then when I got my tools out to film the IACV disconnect it was acting fine. The youtube link for the video showing my bike idling before and after IACV disconnect is: https://youtu.be/uHxmxnRAYw4. Hopefully that works for you guys. And hopefully the bike performs flawlessly tomorrow, at least I'll know what the problem is.

[max]

Good work sir, i like the way the connector disconnected glad it all worked out.
To start it may need a smidge of throttle to get it "off the line" but it will work well i think.
Consider the 2 resistors if the engine light bothers you, it won't affect the engine i think.
Cheers mate and thanks for the video, very effective.

[iamheero_imp]

Thank you for the advice! I am absolutely considering ordering a couple resistors, I hate engine lights! I blame it on the trauma of owning a BMW in the past. If the bike works as intended without that IACV then who needs it.

I'll scoot around tomorrow and see how things go to make sure it's not some rogue vacuum leak. I'll be driving across the city to the beach, then up the coast hitting some canyons, then it's back to town. I'll probably take the long way home and trust the city traffic to make sure the bike is working hard. Hopefully it'll be warm enough to trigger something, it's winter here but that doesn't mean much in Los Angeles.

[iamheero_imp]

Just an update: After the ride with the IACV unplugged, the bike did perform flawlessly with a stable idle, but it was at a higher RPM than normal, probably stayed around 1250-1350rpm after the bike was hot. I'm not sure if that's related to a cooler ambient air as compared to when I unplugged the IACV, though. Any thoughts?

[max]

Good to hear that, i would keep riding for a while , see if anything changes and if it seems too high after that plug the iacv back in and unplug when the engine is at operating temp, at the right rpm and try again, Maybe leave the plastic cover off whilst you are playing with it to make that job easier until you get the right result.
Thanks for the feedback!

[iamheero_imp]

Will do! For what it's worth I've ordered a new IACV and o-ring, it was about $111USD shipped from Partsfish, I figure it's a good chance it's related to my issues at this point.

The next question is how I'm going to get it installed. There's a DIY garage rental space I can use- it just seems like a LOT of work! Any tips from people who have done it themselves would be much appreciated, in looking it up it seems we haven't found any shortcuts to get around removing pretty much everything aft of the throttle body yet.

[max]

There are some descriptions on this forum if you use the search , it is not complicated, just takes time and very basic tools.
The iacv is nice if it works but i have used my 900 hornet for years without adjusting the manual idle adjustment at all without any problems, it is just a very reliable bike with a good injection system which is on standby for now.

[iamheero_imp]

Hey all, just wanted to give a brief update with my situation. It's been a while since I've been riding, the bike kept getting worse so I figured it was time to take it in to a shop. I got the IACV replaced at Honda of Glendale for $330 in labor, I brought the IACV and O-ring I got on partsfish for $~95+tax and shipping. I was relieved, I thought it was going to be a lot more. I have to get more seat time to confirm it's fixed, but seems like it is so far, knock on wood. So for anyone wondering what the CB1100 IACV replacement cost was, I wanted to add my data point.