CB1100 Idle speed instability problem

[ericlo69_imp]

Hi kmoney,

Thanks for your precious suggestion; usually we would not have oscilloscpe on hand, however we can tell dealer your suggestion to identify the root cause. Thanks a lot.

Just thinking out loud, but the problem is either the IACV not functioning or the ECU sending an improper signal (which in itself can be caused by other sensors, like engine temp sensor).

You could back probe the IACV to check for proper function (it's a stepper motor with either two solenoids or one solenoid and a spring) but this would require an oscilloscope with a graph function -- so basically dealer only for most people. All you need to see is if there is a deviation in the signal the computer sends when the bike goes into high or low idle condition.