CB1100 Idle speed instability problem

[pdedse]

Riko, thanks again for your help, having looked at all the clues we have up to this point my suspicion is that we are looking at a tps fault that creeps in over time in a small batch of bikes.

It explains why it takes some time before the fault appears and slowly gets worse.
It explains why it sometimes initiates after driving in a hot situation.
It explains why a wot reset works but only very briefly.
It explains why the kill switch reset works but only briefly.
The bad spot is still there and wears out more over time.

It may be that honda has difficulty finding the fault because their sensors give very little problems due to good engineering ( speculation ) and are not familiar with the problem.

The next problem is the diagnosis itself, even a technician with an oscilloscope would have difficulty finding the bad spot on the sensor, let alone a digital multimeter for this purpose, and because the sensor still reads mostly ok there is no fault code, the ecu does not look for a spotty reading, it only registers very low or high ( wiper broken ) voltage before it sets a code.

So the replacement of the tps or the body and do an a-b comparison is the best test i can come up with so far.

cheers max

Slowly gets worse...does it? Mine started on a warm day last July. First high idle for a few weeks (off and on), then low (off and on), then back to high, back to low, then both go away for a few rides, then back again. A few members report that their issues simply went away. What? How is that possible? Not saying I don't believe them, but that's strange.

What kind of mechanical problems simply "go away"? If a high/low idle issue really goes away, then was there any part that was truly faulty? Or, is it possible there was dirt / bad contact / crimped wire that with vibration or whatever, "corrected itself" and therefore the idle issue "went away"?

Please look at JDVALERO's post #34

And [url=http://cb1100forum.com/forum/showthread.php?tid=10073&pid=187944#pid187944]JDVALERO's post #52

This is one of the few cases that I recall reading where someone actually found something tangibly "wrong", fixed it, and had a positive change--apparently a twisted prong at the TPS connector. He says that after "fixing that the problem went away".

I checked my TPS connector. I didn't see any twisted prong, but I did clean with CRC electronic cleaner and a shot of air to both male/female ends, and then added a small amount of dialectical grease to contact points. 5 rides since and I've had two, brief instances of low idle at 900rpm, both occuring after an a good hour of riding...but nothing like before and upon turn off and restart idle immediately was fine at 1000. No high idle. BUT...the ambient temps are a lot cooler of late, 38-53 degrees instead of 55-75 during October and November.

It's at least something that others can try to see there's any improvement. I may not be able to confirm till warmer days come in about 4-5 months. I do ride throughout the winter and if the problem returns, I'll sqwak about it.

 

[SportsterDoc]

I will continue to assert that there may be more than one cause for idle symptoms.

Also, there is more than one possibility with the TPS:
1. ECM power output from A9 to TPS and MAP does not provide 5 vdc, +/- 0.25 vdc (rare)
2. Any of the three wires to/from TPS damaged (can be checked by resistance values, while wiggling wires)
3. Connector pins/sockets not properly mating (visual inspection, plus unplug/re-plug)
4. Internal contacts are damaged/dirty/surface of resistor has crud (remove TPS and spray contact cleaner inside, alternating with clean compressed air...may or may not work)
5. Resistor damaged (erratic voltage, rather than linear, from closed to open)

Voltage reads will tell a lot.

A poor/damaged connection can make or break with thermal expansion/contraction.
For Harley-Davidson Sportsters with nose cone ignition modules (ended in 2003), intermittent failure was/is common. Typically intermittant failure could be replicated by applying heat from a hairdryer to aid with the diagnosis.

A crack in the 4 way or 5 way vacuum hose connector could be affected by thermal expansion/contraction.

A loose intake hose (8 clamps) could be affected by thermal expansion/contraction.

Crud on the resistor, moved by wipers/contact could move.

If an IACV issue, crud may affect piston operation, even if the stepper motor is being properly driven by the ECM.

Max deserves credit for not only probing the IACV, adding LEDs and producing a video, but for thinking out loud about the TPS to share thoughts for discussion.

Not easy diagnosing by remote...it is very much limited by available input.

 

[max]

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

 

[SportsterDoc]

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Rotating is for initial (0.5 vdc throttle closed) calibration when replacing.
If the center position is not outputting 0.5 vdc throttle closed, I'd check the increased voltage for linearity as it is opened, as well as 4.5 vdc WOT.

As for intermittent issues, see post 7 of this thread:

http://xlforum.net/vbportal/forums/showthread.php?t=2031257&highlight=ckp+connector

The poster is a very high mileage all weather rider.
Re Curly Joe spreadsheet:
736cc issue was low battery voltage
Ericio69 cured by throttle body replacement (no diagnostic help, as problem could be vacuum, IACV or TPS)
Jeff Hawk: IACV replaced
Johnf514 IACV replaced
Mangus replaced IACV and EOT, without curing, leaving vacuum or TPS as possible culprits
Rolls "cured" issue with hard riding, which may have "exercised" IACV, etc.
Sandhog reported temp fix by cycling kill switch, suggesting IACV issue.

 

[pdedse]

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Haha, I am not so optimistic as to call it a cured issue. At least one member has reported that issues disappear over winter only to return in the summer. But every ride free from the high/low idle bug is greatly appreciated, as all are your guys' efforts at pinpointing the matter.

I wish I lived closer to one of you three/four electronic minded members, as I would happily ride by and donate my bike for a weekend to let folks do testing mentioned of late here. I may be able to probe for vacuum leaks as Doc stresses, but I also know my limitations in the realm of electronic diagnosis.

 

[SportsterDoc]

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Haha, I am not so optimistic as to call it a cured issue. At least one member has reported that issues disappear over winter only to return in the summer. But every ride free from the high/low idle bug is greatly appreciated, as all are your guys' efforts at pinpointing the matter.

I wish I lived closer to one of you three/four electronic minded members, as I would happily ride by and donate my bike for a weekend to let folks do testing mentioned of late here. I may be able to probe for vacuum leaks as Doc stresses, but I also know my limitations in the realm of electronic diagnosis.

It needs to be misbehaving, unless there is a stored code.
Have you snugged your intake clamps?

 

[pdedse]

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Haha, I am not so optimistic as to call it a cured issue. At least one member has reported that issues disappear over winter only to return in the summer. But every ride free from the high/low idle bug is greatly appreciated, as all are your guys' efforts at pinpointing the matter.

I wish I lived closer to one of you three/four electronic minded members, as I would happily ride by and donate my bike for a weekend to let folks do testing mentioned of late here. I may be able to probe for vacuum leaks as Doc stresses, but I also know my limitations in the realm of electronic diagnosis.

It needs to be misbehaving, unless there is a stored code.
Have you snugged your intake clamps?

It needs to be misbehaving, unless there is a stored code.
I think this is why the CS manager at the Honda dealership was reluctant to make any promises had I left the bike with them. The week prior to taking it in, the idle was up and down, the day I went in...rock solid.

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Haha, I am not so optimistic as to call it a cured issue. At least one member has reported that issues disappear over winter only to return in the summer. But every ride free from the high/low idle bug is greatly appreciated, as all are your guys' efforts at pinpointing the matter.

I wish I lived closer to one of you three/four electronic minded members, as I would happily ride by and donate my bike for a weekend to let folks do testing mentioned of late here. I may be able to probe for vacuum leaks as Doc stresses, but I also know my limitations in the realm of electronic diagnosis.

It needs to be misbehaving, unless there is a stored code.
Have you snugged your intake clamps?

Not yet; since cleaning the TPS connector the bike has run well (about 2 weeks, 5 rides of 1/2 hour to 2 hours, shorter 10-15 minute rides). I kinda want to let it go for awhile to see if either high or low idle returns. If neither does, maybe we're beginning to isolate the affected area at the TPC connector? If the issue returns, then on to the intake clamps.

 

[max]

pdedse, in the interest of slowly ruling out the iacv , has your 1100 ever deviated from warming up at 1500 rpm?

 

[pdedse]

pdedse, in the interest of slowly ruling out the iacv , has your 1100 ever deviated from warming up at 1500 rpm?

I can't remember what it does during the summer, but now it's cold idle speed starts right at 1500rpm, and then I believe drops to 1200 after 1/4 mile before stabalizing at 1000 shortly after that.

 

[SportsterDoc]

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Haha, I am not so optimistic as to call it a cured issue. At least one member has reported that issues disappear over winter only to return in the summer. But every ride free from the high/low idle bug is greatly appreciated, as all are your guys' efforts at pinpointing the matter.

I wish I lived closer to one of you three/four electronic minded members, as I would happily ride by and donate my bike for a weekend to let folks do testing mentioned of late here. I may be able to probe for vacuum leaks as Doc stresses, but I also know my limitations in the realm of electronic diagnosis.

It needs to be misbehaving, unless there is a stored code.
Have you snugged your intake clamps?

It needs to be misbehaving, unless there is a stored code.
I think this is why the CS manager at the Honda dealership was reluctant to make any promises had I left the bike with them. The week prior to taking it in, the idle was up and down, the day I went in...rock solid.

Thanks pdedse, i was going to ask about this fix, i would not exclude the tps connector, you are now the second to have cured your issue, that i s good news.
Also thanks for the tho links, that helped a lot jdvalero had a low voltage code, so the pin in question was actually the leftmost one, ( +5v ) i think, if it makes bad contact it will open and the voltage will go low.
He correctly states that he THINKS the one he poins at is suspect but it is not.

I like to thank him for taking the picture and posting the fix!

The way the tps connector is installed bothers me a bit, the small wires may be under stress, so it's also a suspect in my opinion and if anyone has a look at theirs be advised to not force the connector in the tps, it should connect fairly easy, if not the contacts could end up mis-aligned and to provide some room in the wiring the tank needs to be lifted and the plastic cover removed with a philips screwdriver.

i also like to stress that trying to adjust the tps by rotating it is not recommended at all unless a very good understanding is achieved on how to proceed, pogun advised this and i would like to repeat his wise words.

Thanks all for the input max

Haha, I am not so optimistic as to call it a cured issue. At least one member has reported that issues disappear over winter only to return in the summer. But every ride free from the high/low idle bug is greatly appreciated, as all are your guys' efforts at pinpointing the matter.

I wish I lived closer to one of you three/four electronic minded members, as I would happily ride by and donate my bike for a weekend to let folks do testing mentioned of late here. I may be able to probe for vacuum leaks as Doc stresses, but I also know my limitations in the realm of electronic diagnosis.

It needs to be misbehaving, unless there is a stored code.
Have you snugged your intake clamps?

Not yet; since cleaning the TPS connector the bike has run well (about 2 weeks, 5 rides of 1/2 hour to 2 hours, shorter 10-15 minute rides). I kinda want to let it go for awhile to see if either high or low idle returns. If neither does, maybe we're beginning to isolate the affected area at the TPC connector? If the issue returns, then on to the intake clamps.

As a fellow/former Sportster rider, we should be accustomed to checking over fasteners regularly. On that basis, it would be good to check the 8 clamps, just as routine maintenance.

 

[SportsterDoc]

More emails between Max and popgun.
Max is favoring the TPS as being the cause of many of the issues.
We are continuing to research a replacement source.

In the meantime, how many CB1100 riders, who have experienced idle instability, have the following conditions:
1. Bike is parked outdoors, uncovered?
2. Bike is ridden in rain, especially heavy rain?
3. Bike is hosed off, occasionally/frequently?

If yes, to any of the above, has the TPS been unplugged (easy thumb release) and contacts checked for corrosion?

Note: Female/outer connector is facing up, which would likely funnel moisture, even though there may be an o-ring (oval) for the male/inner connector to press against.

 

[max]

Sportsterdoc asked if i could put up a picture of my tps and his testclip idea.
This technique is widely used in the automotive faultfinding industry, i think his idea is excellent, practical and very much worth trying.
it involves sharpening a thin steel pin ( folded open paperclip ) and inserting it through the rubber seal that fits around every wire that enters a connector, we all have these.
As corrected by sportsterdoc, a safety pin is another good idea, i like the idea of safety.

We can now safely measure the voltage of the "wiper or moving part " of the tp sensor, it is the red/black middle wire.
insert the pin parallel with the wire into the connector until it stops and touches the metal part of the connector.
using something like crocodile clips connect the pin to the red test probe and connect the black probe to a known good ground, i used the sparkplug metal body for this.

no need to start the engine, just key and stop switch on.

MY FIRST ATTEMPT WAS THE THROTTLE BODY ITSELF FOR GROUND BUT THAT GAVE ME A WRONG READING, BE AWARE!

So here is the picture, not showing the black probe to ground nor the red probe to the white clip.

lets see....max

 

[SportsterDoc]

Thanks, Max

A safety pin from my wife's pincushion works great and saves sharpening a paper clip or =.

The throttle body did not work for a ground, as I think it is plastic.

Sportsterdoc asked if i could put up a picture of my tps and his testclip idea.
This technique is widely used in the automotive faultfinding industry, i think his idea is excellent, practical and very much worth trying.
it involves sharpening a thin steel pin ( folded open paperclip ) and inserting it through the rubber seal that fits around every wire that enters a connector, we all have these.
As corrected by sportsterdoc, a safety pin is another good idea, i like the idea of safety.

We can now safely measure the voltage of the "wiper or moving part " of the tp sensor, it is the red/black middle wire.
insert the pin parallel with the wire into the connector until it stops and touches the metal part of the connector.
using something like crocodile clips connect the pin to the red test probe and connect the black probe to a known good ground, i used the sparkplug metal body for this.

no need to start the engine, just key and stop switch on.

MY FIRST ATTEMPT WAS THE THROTTLE BODY ITSELF FOR GROUND BUT THAT GAVE ME A WRONG READING, BE AWARE!

So here is the picture, not showing the black probe to ground nor the red probe to the white clip.

lets see....max

Too funny!
In North America, we use alligator clips!

 

[pdedse]

More emails between Max and popgun.
Max is favoring the TPS as being the cause of many of the issues.
We are continuing to research a replacement source.

In the meantime, how many CB1100 riders, who have experienced idle instability, have the following conditions:
1. Bike is parked outdoors, uncovered?
2. Bike is ridden in rain, especially heavy rain?
3. Bike is hosed off, occasionally/frequently?

If yes, to any of the above, has the TPS been unplugged (easy thumb release) and contacts checked for corrosion?

Note: Female/outer connector is facing up, which would likely funnel moisture, even though there may be an o-ring (oval) for the male/inner connector to press against.

For me:
1. Bike is parked outdoors, uncovered? Always garaged at night, on a two week trip, parked outside.
2. Bike is ridden in rain, especially heavy rain? Never heavy rain; light rain a few times
3. Bike is hosed off, occasionally/frequently? Have only washed the bike 2x; minimal water used.

In general, bike doesn't get washed much; I didn't see any sign of corrosion at the TPS connector.

 

[SportsterDoc]

More emails between Max and popgun.
Max is favoring the TPS as being the cause of many of the issues.
We are continuing to research a replacement source.

In the meantime, how many CB1100 riders, who have experienced idle instability, have the following conditions:
1. Bike is parked outdoors, uncovered?
2. Bike is ridden in rain, especially heavy rain?
3. Bike is hosed off, occasionally/frequently?

If yes, to any of the above, has the TPS been unplugged (easy thumb release) and contacts checked for corrosion?

Note: Female/outer connector is facing up, which would likely funnel moisture, even though there may be an o-ring (oval) for the male/inner connector to press against.

For me:
1. Bike is parked outdoors, uncovered? Always garaged at night, on a two week trip, parked outside.
2. Bike is ridden in rain, especially heavy rain? Never heavy rain; light rain a few times
3. Bike is hosed off, occasionally/frequently? Have only washed the bike 2x; minimal water used.

In general, bike doesn't get washed much; I didn't see any sign of corrosion at the TPS connector.

Not likely a moisture/corrosion issue for you.
Because of the improvement after cleaning the TPS connector, it may simply be that the contacts were not mating well until disconnected and reconnected, whether cleaned or not.

Had you previously unplugged the TPS?

Do you recall ever bumping the TPS / TPS connector / TPS wirinig?

 

[pdedse]

More emails between Max and popgun.
Max is favoring the TPS as being the cause of many of the issues.
We are continuing to research a replacement source.

In the meantime, how many CB1100 riders, who have experienced idle instability, have the following conditions:
1. Bike is parked outdoors, uncovered?
2. Bike is ridden in rain, especially heavy rain?
3. Bike is hosed off, occasionally/frequently?

If yes, to any of the above, has the TPS been unplugged (easy thumb release) and contacts checked for corrosion?

Note: Female/outer connector is facing up, which would likely funnel moisture, even though there may be an o-ring (oval) for the male/inner connector to press against.

For me:
1. Bike is parked outdoors, uncovered? Always garaged at night, on a two week trip, parked outside.
2. Bike is ridden in rain, especially heavy rain? Never heavy rain; light rain a few times
3. Bike is hosed off, occasionally/frequently? Have only washed the bike 2x; minimal water used.

In general, bike doesn't get washed much; I didn't see any sign of corrosion at the TPS connector.

Not likely a moisture/corrosion issue for you.
Because of the improvement after cleaning the TPS connector, it may simply be that the contacts were not mating well until disconnected and reconnected, whether cleaned or not.

Had you previously unplugged the TPS?

Do you recall ever bumping the TPS / TPS connector / TPS wirinig?

I had not previously unplugged the TPS connector--I didn't even know what it was.
I may have lightly sprayed the area with water after cleaning 2x, but no blasting spray.

jdvalero confirmed for me yesterday that the idle issue has not returned for him since he unplugged his TPS connector and "realigned"? one of the receiving holes of the connector. That was nearly a month ago.

He also mentions that his issue first started after a hard hiway run and wonders if vibration was what brought about a bad contact at the TPS connector.

I hold my breath each ride wondering if the problem will return, but I can tell you that since unplugging and cleaning the TPS connector that I've had the longest run of nearly no issue (slight dip to 900rpm 2x) since the problem started in July.

However, this stretch coincides with much cooler temps. We'll see in time. With Oregon rains and cold days, it's hard to get any rides in, but some dry weather is supposed to come middle of the week.

 

[Wisedrum]

A Honda software update solved my idle problem til now since a few months. The reason for an update were faults in the programming of the fuel injection. So the explanation of the mechatronic. I will see for how long it will last with my 2013 CB.

I recommend everyone with this problem to achieve the same, which will take some effort before trying out other 'solvations' in the meaning of trial and errors attempts in a more or less 'dark room'.

Wisedrum

 

[SportsterDoc]

More emails between Max and popgun.
Max is favoring the TPS as being the cause of many of the issues.
We are continuing to research a replacement source.

In the meantime, how many CB1100 riders, who have experienced idle instability, have the following conditions:
1. Bike is parked outdoors, uncovered?
2. Bike is ridden in rain, especially heavy rain?
3. Bike is hosed off, occasionally/frequently?

If yes, to any of the above, has the TPS been unplugged (easy thumb release) and contacts checked for corrosion?

Note: Female/outer connector is facing up, which would likely funnel moisture, even though there may be an o-ring (oval) for the male/inner connector to press against.

For me:
1. Bike is parked outdoors, uncovered? Always garaged at night, on a two week trip, parked outside.
2. Bike is ridden in rain, especially heavy rain? Never heavy rain; light rain a few times
3. Bike is hosed off, occasionally/frequently? Have only washed the bike 2x; minimal water used.

In general, bike doesn't get washed much; I didn't see any sign of corrosion at the TPS connector.

Not likely a moisture/corrosion issue for you.
Because of the improvement after cleaning the TPS connector, it may simply be that the contacts were not mating well until disconnected and reconnected, whether cleaned or not.

Had you previously unplugged the TPS?

Do you recall ever bumping the TPS / TPS connector / TPS wirinig?

I had not previously unplugged the TPS connector--I didn't even know what it was.
I may have lightly sprayed the area with water after cleaning 2x, but no blasting spray.

jdvalero confirmed for me yesterday that the idle issue has not returned for him since he unplugged his TPS connector and "realigned"? one of the receiving holes of the connector. That was nearly a month ago.

He also mentions that his issue first started after a hard hiway run and wonders if vibration was what brought about a bad contact at the TPS connector.

I hold my breath each ride wondering if the problem will return, but I can tell you that since unplugging and cleaning the TPS connector that I've had the longest run of nearly no issue (slight dip to 900rpm 2x) since the problem started in July.

However, this stretch coincides with much cooler temps. We'll see in time. With Oregon rains and cold days, it's hard to get any rides in, but some dry weather is supposed to come middle of the week.

Loosening the TPS fasteners, motor off, ignition on, voltmeter connected (similar to Max's photo) is the proper way to set the base throttle closed voltage. Arbitrarily moving it is not wise, although I would expect that the throttle calibration procedure may compensate for a minor error in not having 0.5 vdc at throttle closed.

A Honda software update solved my idle problem til now since a few months. The reason for an update were faults in the programming of the fuel injection. So the explanation of the mechatronic. I will see for how long it will last with my 2013 CB.

I recommend everyone with this problem to achieve the same, which will take some effort before trying out other 'solvations' in the meaning of trial and errors attempts in a more or less 'dark room'.

Wisedrum

What was the upgrade date of the software?
What is the software number?
Does 2014 model already have that update?

A Honda software update solved my idle problem til now since a few months. The reason for an update were faults in the programming of the fuel injection. So the explanation of the mechatronic. I will see for how long it will last with my 2013 CB.

I recommend everyone with this problem to achieve the same, which will take some effort before trying out other 'solvations' in the meaning of trial and errors attempts in a more or less 'dark room'.

Wisedrum

So, are you recommending that no one follow the diagnostic instructions per the Honda Factory Service Manual?

The last few pages of this very long thread have been a quest for empirical data to perhaps allow remote diagnosis...not trial and error.

A. Snugging clamps on the intake hoses, to minimize the chance of a vacuum leak, is a standard motorcycle maintenance procedure. A follow-up check is to apply an unlit propane torch (or WD-40, if you don't mind the mess) while the engine is running, to check, for a change in idle speed.

B. Measuring resistances and voltages, per the FSM is standard diagnostic procedure.

C. Checking for active or stored codes is standard diagnostic procedure.

What suggestions are you labeling as trial and error?

What would you suggest if a software upgrade does not solve the issue?

At this point, it is likely that there are three possible (or combined) issues for high/low idle issues:

1. TPS sensor / TPS connector / TPS wiring / voltage to TPS from ECM.

2. IACV motor / IACV plunger operation / IACV wiring

3. Vacuum leak associated with intake manifold tubing / intake hose clamps loose.

Many, many times carb removal and reinsertion without lubrication (water, diluted liquid soap or spit) has resulted in a vacuum leak on Sporsters (Keihin CV40 into single hose to manifold to both cylinders). Many, many times the vacuum line on pre 2006 models to the vacuum operated petcock and the Y to the VOES (Vacuum Operated Electrical Switch which signals advance/retard to ignition module) on pre 2004 models has been an issue.

Although I have been wrenching for over half a century, I certainly do not know everything...I am still learning...but what has been posted is directly from or based upon the FSM.

I absolutely despise throwing parts at an issue and a very expensive throttle body assembly does that for 2 1/2 of the 3 issue categories.

Although Harley, Triumph and Moto Guzzi have two year warranties, Honda USA is only one year. We don't want idle issues to push a CB1100 rider into an unnecessary throttle body replacement, simply because full diagnostics have not been done.

 

[Wisedrum]

I cannot give you the wanted details.
I don't have them. Just one, the upgrade was made in the mids of October this year.

I describe the way my Honda got its update.
A telefon call with the Honda management informed me, that an update was available. When I found time later on I drove to the nearest Honda dealer to let it be played on my CB. He knew nothing. So he gathered information and got the update on a cd. We fixed a date, I waited the time my Honda was installed and after 2 hours we were through with it. When I asked for the price of the action the chief of the Honda shop told me I have to pay nothing. Honda did it under warranty although my CB has run out of it because they fixed bugs.

No cash, no serial number but a machine that functions well again.

In our German forum is a member who's trying to find out, if Honda has developed something comparable for the follwing model like the EX. I don't no how successful he has been. After writing something about his problem here and in Germany he did not continue his discreption of how things developed. In a way he was not lucky but hopeful.

So, ask your dealer or even better the Main Honda US Department. They should know something about the update to be on the market or not.

Doing diagnostics can be fine. I did mine as good as I could and tried out different proceedings. Talked to people, read a lot here in this thread. But all curing was not successful. Maybe it helped a bit. Until now the only thing that has been really helpful was the systsem update on my Honda. Maybe CBs are not a alike and need different treatment. I don't think so, they are equal constructed machines. The engineer that informed me let me know, that the update will only cure low idle problems not high ones. Strangely enough. My Honda mutated its idle behaviour after my attempts from high into low ones. So bad so good for the update.....all seems to be obscured and hidden in digital clouds and mysteries, I as a normal human being not being a motorbike engineer am not able to understand all aspects of this issue. Not even single parts of it. The only thing I knew is, that the CB should run well right from start over a long time without any faults in its conception. I experienced misfunctions with other vehicles I bought as new ones and used ones with warranty. I fought with the manufacturers and dealers til they run well, even if it took my time and nerves. It was worth the effort. Same with the CB.

Wisedrum

 

[beardyweirdy@me.com_imp]

Just to note again, as it's probably now lost in the murky depths of this Mega Thread, I had the updated software installed on my 2014EX. As per Wisedrums experience, it came on a CD from Honda UK to my dealer. They plugged up the bike and updated. Never had the low idle since....
I asked for a number for the software but didn't get anything. No notes In the service book.
Sorry to not offer you anything, but just wanted to say it was available in the U.K. Also and for the 2014EX