CB1100 Idle speed instability problem

[SportsterDoc]

Max posted this 17 Dec 2017 in postt 21 of "diagnostic trouble codes and sensor testing" thread:

http://cb1100forum.com/forum/showthread....Diagnostic

"Bonus footage; iacv operation on my bike, as usual a bit vague, the video editing program had trouble at 5% slow motion but what happens is ; on startup the iacv opens 65 steps and then closes 12 steps with a cold engine and 35 wiith a warm engine.

This happens in the blink of an eye as demonstrated at the very end of the video so i slowed it down to count the steps and direction, open and close.

the ecu does not know what position the iacv is at startup , so it always commands the valve open with 65 pulses, it then makes a decision to close x many steps based on the temperature of the eot sensor."

Doc, you know, we were just joking about the creds back then. Like we tend to do here.

Found the needles, have some jumpers ready and a long one for the proper ground so as to use 2 probes at once.

I know and we were still getting acquainted...and a couple times I probably overdid the background and appreciate Moderator deletion, at my request. At the risk of perhaps having to again do so, I will share this:

In 1985, I was asked for input on an automation project, for which I sold the DC motor, gear reducer and brake.

The machine, one of many built by Calmation's predecessor, inserted .025 square pins (bandolier fed) into an AT&T backplane at the rate of 20 pins per second: 5 pin head, dual heads, 2 insertions per second.

The challenge was to increase speed, but when motor speed was increased, the brake (sensor activated for positioning) would overheat and cause position drift. A larger brake would dissipate the heat, but created an inertia problem and advancing the timing of sensor activation was inconsistent.

My solution was not at all technical: I simply suggested blowing air on the brake to prevent overheating. It worked...and was not previously discussed in either Warner (electric clutch/brakes) nor Horton (pneumatic clutch/brakes) factory technical seminars.

The moral of this story is to recommend not overthinking a problem or its solution.
Correction
I forgot about DTC 29-1, which is most likely connector or wiring issue, not a positional error.
I would correct post 1042 and 1047 but too much time has elapsed for me to do so.

Doc, What do you want the posts to say? Ferret or I will edit them for you.

Doc, What do you want the posts to say? Ferret or I will edit them for you.
Thank you.
1042 Pls delete "I am not aware of a DTC for the IACV" there is one, DTC 29-1, but it is not related to position error.

1047 "It has no feedback, unlike a servo motor with an encoder, hence no associated DTC" add "FOR POSITION ERROR"