CB1100 Idle speed instability problem

[Lord Popgun]

I’ll look into the videosmaller thing, Speed. Right now I’m waiting for it upload to the iCloud so I can mess with it on my iPad or MacBook. Much easier than the phone. Only the 10 second one has shown up so far.

In the meantime I’ll going out in the garage and see what happens when I open the throttle gently. The video for that should be pretty small.

I’

[Cormanus]

I don’t use iCloud, but you may be able to give access to someone to download a file. Microsoft OneDrive or Google Drive would a allow it.

[Lord Popgun]

Cormanus, I don’t know how to do that, if its possible. The smaller thing looks pretty easy though.

You may not use iCloud, but your devices are using it. Holds backups, copies of your pics, music, etc. Its how you take a pic on, say, your phone and it shows up on your MacBook and iPad.

[Cormanus]

Popgun, I’ll send you an email.

[max]

L.P. you can usually create a clickable link to any web page you are on by;

Double clicking on the browser ip-adress window ( with the http etc in it ),which then highlights ( changes color ) and right clicking on the highlighted text and leftclick "copy" , you can then open a message like this and "paste" the link into the message, it will show as a red clickable link in the message like this;
http://cb1100forum.com/forum/showthread....#pid264766

When anybody clicks on it they will open a new window and go to that webpage the link was obtained from.

You probably already know this but just in case....

Ill now go back into my little corner and be quiet again.

[Cormanus]

I've just had a bit of a hunt around iCloud, my lord Popgun and I think I can help you make it work.

Max, your method will work with many web pages, but it may not (probably should not) work with a link to a file in cloud storage if it's protected. It looks possible to give people permission to access files stored in iCloud Drive.

[Speed_imp]

I’ll look into the videosmaller thing, Speed. Right now I’m waiting for it upload to the iCloud so I can mess with it on my iPad or MacBook. Much easier than the phone. Only the 10 second one has shown up so far.

In the meantime I’ll going out in the garage and see what happens when I open the throttle gently. The video for that should be pretty small.

I’

Yes it is clear, working as designed, thanks Popgun. The only thing is that while engine running a pulse train appears when opening the throttle that lowers the idle speed. This video is clue to understand what happens to my bike, specially at 0:35 very clear.

https://www.youtube.com/watch?v=aT2bjVxi0qo

[Lord Popgun]

Max, thanks. That I knew. I don’t know how to make a WORD a link. Like, click on WORD and it goes somewhere. I guess it isn’t hard as everybody does it.

Meanwhile back to the issue at hand.

I started the bike and let it warm up to 1100rpm. Was fun watching the ECU issue a pulse or 2 every now and then and seeing the RPM needle fall a little. If I had the diagnostic tool running I could watch the step count too.

Anyway, after it warmed, I did the gently open the throttle thing. The IACV would receive a small pulse train of around 4 pulses as it came off idle. A time or two I did not see anything. But mostly I did. I didn’t video it yet, wanted to see what would happen first.

[SportsterDoc]

I’ll look into the videosmaller thing, Speed. Right now I’m waiting for it upload to the iCloud so I can mess with it on my iPad or MacBook. Much easier than the phone. Only the 10 second one has shown up so far.

In the meantime I’ll going out in the garage and see what happens when I open the throttle gently. The video for that should be pretty small.

I’

Yes it is clear, working as designed, thanks Popgun. The only thing is that while engine running a pulse train appears when opening the throttle that lowers the idle speed. This video is clue to understand what happens to my bike, specially at 0:35 very clear.

https://www.youtube.com/watch?v=aT2bjVxi0qo

I would not expect the idle air control valve to have much effect once the throttlebody(ies) opens.

It sounds as though the fuel injectors are not compensating properly for the throttle bodies opening.

One possibility is an incorrect setting on the throttle position sensor...hence the TPS is not properly informing the ECM of the throttle position.

If that is the case, the first step would do a TPS reset procedure and if that has no effect, then follow the manual instructions for checking the voltage for TPS fully closed and fully opened.

http://cb1100forum.com/forum/showthread....=Tps+reset

[url=http://cb1100forum.com/forum/showthread.php?tid=8120&page=66]http://cb1100forum.com/forum/showthread....20&page=66

Post 651: A, B & C

From post 617 in this thread

These are basic TPS checks condensed from FSM 5-23 and 5-24 (no Honda MCS diagnostic instrument needed):

DTC 8-1 TP (Throttle Position) sensor low voltage
With ignition switch on and stop/run on, probe sensor contacts to verify steady voltage increase from throttle fully closed to throttle fully open.
With ignition switch off, disconnect the connector, then with ignition switch on and stop/run on, measure voltage between connector pins black/yellow (+) to black/green (-) for 4.75 to 5.25 vdc.
If no voltage, with ignition off, check continuity on black/yellow to ECM connector, for continuity of center pin sensor output black/red wire to ECM connector and for no continuity (infinity) of black/red wire to ground.

DTC 8-2 TP (Throttle Position) sensor high voltage
With ignition switch off, disconnect the connector, measure sensor resistance between black/red and black green of 0.5 to 1.5 K ohms. Then with ignition switch on and stop/run on, measure voltage between connector pins black/yellow (+) to black/green (-) for 4.75 to 5.25 vdc.

[Speed_imp]

Finally I uploaded to my channel the video Lord Popgun made with the control signal from the ECU to the IACV valve from his known good idle speed adjustment bike. Engine sound can be heard also so you can make yourself an idea of what is happening, and with both channels to monitor the signal of each one of the coils. I love it! Thanks man! With that I can definately rule out the ECU is screwed, my control signals are as expected, so there is only one way for me to go for repairing it. Yes. Replacing the IACV!! I will, keep you posted. This is the link to the video Lord Popgun made:

https://youtu.be/aYuP9DtZOsA

I’ll look into the videosmaller thing, Speed. Right now I’m waiting for it upload to the iCloud so I can mess with it on my iPad or MacBook. Much easier than the phone. Only the 10 second one has shown up so far.

In the meantime I’ll going out in the garage and see what happens when I open the throttle gently. The video for that should be pretty small.

I’

Yes it is clear, working as designed, thanks Popgun. The only thing is that while engine running a pulse train appears when opening the throttle that lowers the idle speed. This video is clue to understand what happens to my bike, specially at 0:35 very clear.

https://www.youtube.com/watch?v=aT2bjVxi0qo

I would not expect the idle air control valve to have much effect once the throttlebody(ies) opens.

It sounds as though the fuel injectors are not compensating properly for the throttle bodies opening.

One possibility is an incorrect setting on the throttle position sensor...hence the TPS is not properly informing the ECM of the throttle position.

If that is the case, the first step would do a TPS reset procedure and if that has no effect, then follow the manual instructions for checking the voltage for TPS fully closed and fully opened.

http://cb1100forum.com/forum/showthread....=Tps+reset

http://cb1100forum.com/forum/showthread....20&page=66

Post 651: A, B & C

From post 617 in this thread

These are basic TPS checks condensed from FSM 5-23 and 5-24 (no Honda MCS diagnostic instrument needed):

DTC 8-1 TP (Throttle Position) sensor low voltage
With ignition switch on and stop/run on, probe sensor contacts to verify steady voltage increase from throttle fully closed to throttle fully open.
With ignition switch off, disconnect the connector, then with ignition switch on and stop/run on, measure voltage between connector pins black/yellow (+) to black/green (-) for 4.75 to 5.25 vdc.
If no voltage, with ignition off, check continuity on black/yellow to ECM connector, for continuity of center pin sensor output black/red wire to ECM connector and for no continuity (infinity) of black/red wire to ground.

DTC 8-2 TP (Throttle Position) sensor high voltage
With ignition switch off, disconnect the connector, measure sensor resistance between black/red and black green of 0.5 to 1.5 K ohms. Then with ignition switch on and stop/run on, measure voltage between connector pins black/yellow (+) to black/green (-) for 4.75 to 5.25 vdc.

I would not expect the idle air control valve to have much effect once the throttlebody(ies) opens.

It sounds as though the fuel injectors are not compensating properly for the throttle bodies opening.

One possibility is an incorrect setting on the throttle position sensor...hence the TPS is not properly informing the ECM of the throttle position.

If that is the case, the first step would do a TPS reset procedure and if that has no effect, then follow the manual instructions for checking the voltage for TPS fully closed and fully opened.

[url=http://cb1100forum.com/forum/showthread.php?tid=11984&highlight=Tps+reset]http://cb1100forum.com/forum/showthread.php?tid=11984&highlight=Tps+reset

[url=http://cb1100forum.com/forum/showthread.php?tid=8120&page=66]http://cb1100forum.com/forum/showthread....20&page=66

Post 651: A, B & C

From post 617 in this thread

These are basic TPS checks condensed from FSM 5-23 and 5-24 (no Honda MCS diagnostic instrument needed):

DTC 8-1 TP (Throttle Position) sensor low voltage
With ignition switch on and stop/run on, probe sensor contacts to verify steady voltage increase from throttle fully closed to throttle fully open.
With ignition switch off, disconnect the connector, then with ignition switch on and stop/run on, measure voltage between connector pins black/yellow (+) to black/green (-) for 4.75 to 5.25 vdc.
If no voltage, with ignition off, check continuity on black/yellow to ECM connector, for continuity of center pin sensor output black/red wire to ECM connector and for no continuity (infinity) of black/red wire to ground.

DTC 8-2 TP (Throttle Position) sensor high voltage
With ignition switch off, disconnect the connector, measure sensor resistance between black/red and black green of 0.5 to 1.5 K ohms. Then with ignition switch on and stop/run on, measure voltage between connector pins black/yellow (+) to black/green (-) for 4.75 to 5.25 vdc.
I checked the values of resistance and voltage of the TP sensor and they are within specs. Resistance rising up evenly while opening throttle. If I disconnect the TP sensor (which I did minutes ago) the MIL light goes on and disables the operation of the IACV, no signal to it, then I don't have low idle issues. If I disconnect the IACV I dont have low idle issues also. I am pretty shure the TP sensor is OK, ruled out. And ECU also ruled out, I only can try with a Software update before starting the IACV replacement. Ouch!