CB1100 Idle speed instability problem

Well sounds like you already talked yourself out of trying- but there are plenty of places you can buy an updated ECU from online and return it if the problem still occurs.
 
PowerDubs_imp said:
Well sounds like you already talked yourself out of trying- but there are plenty of places you can buy an updated ECU from online and return it if the problem still occurs.
Click to expand...
Well if that's the case where I can return it, where should I get it from? High dollar electronic parts like that are usually non-refundable
 
Is Nachodaddy the first owner of a 2013 to report this problem?
 
Max, I am confused.
You said " i then put another two 470 ohm resistors in parallel with the first pair and the e.c.u. was happy with the 470:2= 235 ohm load per winding of the iacv and the c.e.l. did not light..... i think it is worth connecting two 100 microfarad capacitors across the two windings, this may store/release enough energy to motivate the iacv by making the pulse last longer."
_______________________________________

Are you replacing the IACV with the resistors/capacitors?
Do you remove the IACV?
If the IACV is not removed, how do you connect the capacitors across the two windings?
Thanks for all the work/brainpower you have already committed to this and please forgive my electronic incapacity.
:thanks:
 
Cheers Nacho, these are two different idea's;

Idea 1; remove iacv connector ( when the engine has idled normally when switched off so the iacv is in a good position) and insert two 220 ohm resistors as in the picture and leave the iacv disconnected, this will disble the limp mode that you mentioned since the ecu monitors the iacv current and decides it has or has not got a problem and limits the engine to 5000 rpm.

Idea 2; connect two capacitors parallel with the iacv coils, this might hopefully charge ( when the pulse is present ) and release ( when the pulse has stopped ) the capacitor's energy into the iacv ( the pulse appears longer to the iacv ) .

A bit of a trick but i would stick the capacitor's legs right besides the wires to the connector through the " weather pack " which is the silicon rubber seal which stops moisture entering the connector on the wire side.
These seals are generally used by diagnostic techs who insert a test pin or a paper clip beside the wire, the seal will hold the pin in place and the pin will make contact at some point when inserted at the end of travel of the connector, this can also be done with the capacitor leads as a temporary test and go from there.

This second idea is just a theory of me which may or may not work.
The value of the capacitor is arbitrarily ( i just thought this may work ) and you have to observe the polarity of the electrolytic capacitors, again; just an idea.

Good point as i was not clear enough on the second idea, i have not experienced the idle thing personally so i am limited in the things i can suggest, all of this is my best guess and some of it i have verified, like the resistors.

Since it is not always possible for me to know the ability or sense of direction they want to go in of the guys at the other end of the world i just put forward some hints which may work for them and maybe be of assistance to some which are reading the posts, some pick it up some don't that's fine too.
 
Thank you Max, I am a great admirer of your work. I understand now. I would try the first approach, but there is a catch. The engine no longer idles at what anyone would consider normal. At start-up, it idles about 1500 and after I ride a few minutes, when I next come to a stop, it is at 2K. I can ride as much as I like after that, as long as I am careful about the idle. So, since the engine has not idled at "normal" before switching off, do you think there is any chance #1 will work? Or will it simply apply 2K as it's new "normal?"
 
So if you start the engine and it warms up at 1500 does it not gradually slow down to 1050 or another acceptable level? when sitting still?
Also try disconnecting the engine temperature sensor ( just below the cam chain tensioner at the back of the cylinders ),
with some combination it may decide to come down to 1050 at which point you can shut it down with the ignition key and unplug the iacv.

As you know the butterfy valves of the throttle body are closed at idle, all the iacv does is supply the " correct "
amount of air passed each valve and has an individual adjustment screw ( 4 in total ) under the throttle body to
adjust the airflow to the individual cylinders and is measured with 4 vacuum gauges to make the engine run with an equalized amount of mixture to make it run smooth, i have checked my 4 set screws with 4 vacuum gauges and all was perfect so i left it alone, normally these do not need service unless the idle is rough and thus " out of sync ".

There is no information in the service manual about this, all it says is " don't touch " but if the tech knows what he is doing.........
 
max_imp said:
So if you start the engine and it warms up at 1500 does it not gradually slow down to 1050 or another acceptable level? when sitting still?
Also try disconnecting the engine temperature sensor ( just below the cam chain tensioner at the back of the cylinders ),
with some combination it may decide to come down to 1050 at which point you can shut it down with the ignition key and unplug the iacv.

As you know the butterfy valves of the throttle body are closed at idle, all the iacv does is supply the " correct "
amount of air passed each valve and has an individual adjustment screw ( 4 in total ) under the throttle body to
adjust the airflow to the individual cylinders and is measured with 4 vacuum gauges to make the engine run with an equalized amount of mixture to make it run smooth, i have checked my 4 set screws with 4 vacuum gauges and all was perfect so i left it alone, normally these do not need service unless the idle is rough and thus " out of sync ".

There is no information in the service manual about this, all it says is " don't touch " but if the tech knows what he is doing.........
Click to expand...
Hi Max, I would like to connect the vacuum gauge, but I don't understand where the 4 connections are, I only see 3, I don't see the connection for the first cylinder on the right. could you indicate it to me, perhaps with a diagram?
Thanks
 
Enzofour_imp said:
max_imp said:
So if you start the engine and it warms up at 1500 does it not gradually slow down to 1050 or another acceptable level? when sitting still?
Also try disconnecting the engine temperature sensor ( just below the cam chain tensioner at the back of the cylinders ),
with some combination it may decide to come down to 1050 at which point you can shut it down with the ignition key and unplug the iacv.

As you know the butterfy valves of the throttle body are closed at idle, all the iacv does is supply the " correct "
amount of air passed each valve and has an individual adjustment screw ( 4 in total ) under the throttle body to
adjust the airflow to the individual cylinders and is measured with 4 vacuum gauges to make the engine run with an equalized amount of mixture to make it run smooth, i have checked my 4 set screws with 4 vacuum gauges and all was perfect so i left it alone, normally these do not need service unless the idle is rough and thus " out of sync ".

There is no information in the service manual about this, all it says is " don't touch " but if the tech knows what he is doing.........
Click to expand...
Hi Max, I would like to connect the vacuum gauge, but I don't understand where the 4 connections are, I only see 3, I don't see the connection for the first cylinder on the right. could you indicate it to me, perhaps with a diagram?
Thanks
Click to expand...
Hi Max, I would like to connect the vacuum gauge, but I don't understand where the 4 connections are, I only see 3, I don't see the connection for the first cylinder on the right. could you indicate it to me, perhaps with a diagram?
Thanks


Howzat Enzo?

Make sure the gauges are indicating the same reading, i use a 4 way aquarium hose connector, produce a vacuum on 3 gauges and then swap one for the last gauge, that way i know the readings are true.
i also use clamps on the rubber hoses so the gauges don't shake themselves to bits and have gentle movement.
 
lol - over the years I have formed a perception that every time max is up to the challenge to solve a forum question, some CB1100 will get a quick teardown later that day.

I am curious the day a like question is asked:

" ... max? The main journal counter-masses, what are their weight? ... "

Max: " ... uh, that will take me some time. Let me get back to you after my egg salad sandwich ... "

:)
 
Hey PowerDubs, you mentioned that there are "plenty of places" that would allow me to test a new part, and return if it doesn't work? Since you mentioned it, do you have a parts source that will back that claim up?

I don't mind dropping $700 on a new ECU if that's all it is. I can do an ECU swap in a few minutes. I'll lose less money fixing the bike than trading it in. However, betting that a new ECU will fix it isn't good enough for me.

PowerDubs_imp said:
Well sounds like you already talked yourself out of trying- but there are plenty of places you can buy an updated ECU from online and return it if the problem still occurs.
Click to expand...
 
Thanks for the response!

Interesting, I assumed those outlets would have some sort of stipulation for the return of electronics such as an ECU. I'll look into it and if everything's straight, I might just buy one and see what kind of result we can net.
 
Like anything else in the world- there are technicalities to anything.

Like pulling up to a cop, rolling down your window- and asking him if your license plate frame is illegal.

Don't ask, don't tell.

Just don't bang it up / scratch it.
 
Enzo there are 4 calibrated gauges required together with the knowledge to deal with the interaction of the iacv positions.

From the question i think you may not have done a carb/ throttle body sync before, so before changing anything i would suggest to watch several yt video's to find out what's involved, how to do it and why.
Throttle sync is only required when the engine is warm and at idle, there is no other reason to adjust the sync adjustment which is why Honda does not supply service info, they want to avoid the risk of getting it wrong which is easy to do, the adjustment screws are not fixed like the old carburettors so by adjusting too much you can drift out of range and end up with a rich or lean mixture.
With carburetors you adjust the amount of fuel mixture, with a throttle body you only adjust the amount of air per cylinder, there is a difference.

For instance when i bought my cb919 the engine sounded like a harley at idle, the engine only ran on 2 cylinders, it took me a while to work out why, and after syncing the throttlebody with the 4 gauges it started to run like it should have; somebody mis-understood what they did and got it wrong.
Once i had the vacuum gauges installed and started the engine it was very apparent that the sync was off.
All four cylinders have the same capacity so they produce the same amount of vacuum at each intake stroke at the intake when the valves open, this amount can be measured with 4 individual vacuum gauges and adjusted so they read the SAME amount of vacuum supplied through the iacv and adjusted ( equalized ) by the 4 screws under the throttle body.

As soon as the throttle is opened slightly the butterfly valves and the tps start doing their job and the idle screws are no longer of any importance, they are only required when the butterfly valves are closed.

You can then verify this by using a piezo electric pressure sensor in the exhaust and watch the pulses it produces with each exhaust stroke which should be equally the SAME, you do need an automotive oscilloscope for this check so you can record and watch the pulse train.
Hope this helps.

My advice; if there is no problem don't introduce one.
With all respect for your ability and thanks for all your help, i appreciate it; cheers
 
max_imp said:
Enzo there are 4 calibrated gauges required together with the knowledge to deal with the interaction of the iacv positions.

From the question i think you may not have done a carb/ throttle body sync before, so before changing anything i would suggest to watch several yt video's to find out what's involved, how to do it and why.
Throttle sync is only required when the engine is warm and at idle, there is no other reason to adjust the sync adjustment which is why Honda does not supply service info, they want to avoid the risk of getting it wrong which is easy to do, the adjustment screws are not fixed like the old carburettors so by adjusting too much you can drift out of range and end up with a rich or lean mixture.
With carburetors you adjust the amount of fuel mixture, with a throttle body you only adjust the amount of air per cylinder, there is a difference.

For instance when i bought my cb919 the engine sounded like a harley at idle, the engine only ran on 2 cylinders, it took me a while to work out why, and after syncing the throttlebody with the 4 gauges it started to run like it should have; somebody mis-understood what they did and got it wrong.
Once i had the vacuum gauges installed and started the engine it was very apparent that the sync was off.
All four cylinders have the same capacity so they produce the same amount of vacuum at each intake stroke at the intake when the valves open, this amount can be measured with 4 individual vacuum gauges and adjusted so they read the SAME amount of vacuum supplied through the iacv and adjusted ( equalized ) by the 4 screws under the throttle body.

As soon as the throttle is opened slightly the butterfly valves and the tps start doing their job and the idle screws are no longer of any importance, they are only required when the butterfly valves are closed.

You can then verify this by using a piezo electric pressure sensor in the exhaust and watch the pulses it produces with each exhaust stroke which should be equally the SAME, you do need an automotive oscilloscope for this check so you can record and watch the pulse train.
Hope this helps.

My advice; if there is no problem don't introduce one.
With all respect for your ability and thanks for all your help, i appreciate it; cheers
Click to expand...
**
PowerDubs_imp said:
"My advice; if there is no problem don't introduce one."


Sage advice quite often.
Click to expand...
Agree with both...if NFF = do not tinker
 
max_imp said:
Enzo there are 4 calibrated gauges required together with the knowledge to deal with the interaction of the iacv positions.

From the question i think you may not have done a carb/ throttle body sync before, so before changing anything i would suggest to watch several yt video's to find out what's involved, how to do it and why.
Throttle sync is only required when the engine is warm and at idle, there is no other reason to adjust the sync adjustment which is why Honda does not supply service info, they want to avoid the risk of getting it wrong which is easy to do, the adjustment screws are not fixed like the old carburettors so by adjusting too much you can drift out of range and end up with a rich or lean mixture.
With carburetors you adjust the amount of fuel mixture, with a throttle body you only adjust the amount of air per cylinder, there is a difference.

For instance when i bought my cb919 the engine sounded like a harley at idle, the engine only ran on 2 cylinders, it took me a while to work out why, and after syncing the throttlebody with the 4 gauges it started to run like it should have; somebody mis-understood what they did and got it wrong.
Once i had the vacuum gauges installed and started the engine it was very apparent that the sync was off.
All four cylinders have the same capacity so they produce the same amount of vacuum at each intake stroke at the intake when the valves open, this amount can be measured with 4 individual vacuum gauges and adjusted so they read the SAME amount of vacuum supplied through the iacv and adjusted ( equalized ) by the 4 screws under the throttle body.

As soon as the throttle is opened slightly the butterfly valves and the tps start doing their job and the idle screws are no longer of any importance, they are only required when the butterfly valves are closed.

You can then verify this by using a piezo electric pressure sensor in the exhaust and watch the pulses it produces with each exhaust stroke which should be equally the SAME, you do need an automotive oscilloscope for this check so you can record and watch the pulse train.
Hope this helps.

My advice; if there is no problem don't introduce one.
With all respect for your ability and thanks for all your help, i appreciate it; cheers
Click to expand...
Ciao Max, come puoi vedere non sono proprio un principiante :)

5efde316e31cb5dc6054cfb30e34aa9c.jpg


Ma questo era un motore a carburatori, sui corpi farfallati si sono un principiante.

Il mio CB1100 non ha problemi, ma vorrei sapere dove precisamente collegare i tubi del vacuometro perche ci sono diversi tubi sul corpo farfallato e non vorrei sbagliare.

Mi piacerebbe controllare se le leggere vibrazioni al manubrio e agli specchi, che ho a motore caldo e in folle, sono fisiologiche o è il minimo non perfettamente alliniato.
 
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