CB1100 Idle speed instability problem

[SportsterDoc]

Dave

If you will provide resistances of the EOT at a couple sensor temperatures...

Then if someone with a FSM will post the acceptable ranges, we can determine if it is an EOT sensor issue.

Temperature sensors have various ranges, but all I have seen have max resistance cold and minimum resistance hot.

On a 5 vdc circuit, it will output 4 point something vdc cold and point something vdc hot. If the unit is faulty and/or a poor connection (causing voltage drop), a lower than scale read will fool the ECU into thinking it is too hot and the ecu may take counter measures.

Also, someone with a FSM, is there a trouble code for EOT out of range hi or out of range low?

Hi Sportsterdoc. I replaced the EOT sensor and it did nothing. This sensor is extremely sensitive to temperature - just holding it in your hand will raise the temperature enough to considerably change the resistance. Both my old and new sensors checked out according to the Honda service manual (but my body temperature would cause them to go out of spec). If I hadn't already replaced the EOT sensor I might try your suggestion, although it may be difficult to record an accurate temperature. Thank you for the suggestion.

My bike has been on a high idling kick. Right about 1400. A little irritating


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Can you please contact Honda and let them know? The phone number and contact name is in this thread. Thank you.
Some observations; engine does not start with eot sensor disconnected and engine light comes on, it just stutters.

Hi Max. When I disconnect the EOT sensor on my 2014 Dlx the check engine and temperature lights both go on, but the bike starts and runs fine. Actually, when it is experiencing either the high idle or low idle condition unplugging the EOT sensor will cure the problem - but I must first turn the bike off with the key before unplugging it, and then restart it. Interesting that your bike will not restart. I wonder how other members bike would react to unplugging the EOT sensor?
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Dave
There is likely more than one issue affecting low or high idle.
Even though Max has documented a direct linear correlation between EOT output and idle speed, that does not seem be your issue.

The resistance value is at 20C. Warming it in your hand is expected to change the resistance.

Hi Dave, good to hear from you again.

A question; in general would you agree that the issue starts gradually at some point and then gets progressively worse?

Not trying to put words in your mouth , just thinking in one direction and one step at a time if that makes sense..

Cheers max

If that is the case it is explainable with several options:
a. Sensor deterioration
b. Loose connection/broken wire worsening
c. Vacuum leak increasing/fluctuating

You all may get weary of me mentioning vacuum leaks, but they are very common on the XLForum.