Any long-term findings on the Guhl ECM reflash?

[glarson3]

I know several people were getting their ECM reflashed to eliminate the stumble. My bike has experienced this from after a few thousand miles. If there's a solution out there that has been tested over several thousand miles with success I'm ready to bite. Don't tell me to just let the bike reach temperature. It doesn't matter if the bike shows at temperature, or not. I can ride it hundreds of miles, stop for 15 minutes, get back on it, and it will stumble.

[Cruiseman]

I have had mine done twice. The second time was a few weeks ago. My first one did not solve the stumble issue. I went with the most aggressive program on the second attempt. Even though the stumble is still present, you have to really work at it to feel it now. But, on the downside, so much fuel has been dialed in at low RPMs that the mileage has gone to crap. Don warned me that mileage would go down, but I did not expect it to be this bad. I am lucky if I can get 36 on the highway and 28 in town. I may send it back and have it dialed back.

[jmohme]

I would really like to know what has changed from 2010 to now.
I don't have a stubble issue, but I would like to know what the root cause is.

[srt8-in-largo]

If the parts list show no mechanical changes, it can only be one thing: programming.

[Cruiseman]

I think all of the great minds on this forum, and other forums, have narrowed it down to either ECU programming, faulty sensors, or both.

[Rocky]

My 04 ran fine, I was able to track down the original ECU from a 2001 bike (I have all the ECU part numbers from day one). I only paid $89 delivered.

My throttle is snappier than the 04 unit. now with my Loops/Daytona mufflers it is one sweet set up now.

[MMR]

I think all of the great minds on this forum, and other forums, have narrowed it down to either ECU programming, faulty sensors, or both.

And it is with great respect, and I say this very politely...I disagree. I think all those "great minds" are over thinkiing this issue, and spending unnecessary money, when the most common denominator is a much less costly repair. But...I have voiced my opinion on this matter before, and of those that have listened...the vast majority have resolved their bike stumble. Not 100 % of the bikes have been fixed, but enough to show it is a leading factor in causing the stumbling. Personally, I think the ECU/ECM is a bunch of hogwash (something that should be used to clean an Electra Glide) (humor intended), but....ultimately each of us gets to spend our money the way we each choose to.

The bottomline for me is...I sincerely hope that each and every Wing out there gets the stumble issue resolved...peacefully, and at a cost that is not too negative to the bike's owner.

[MMR]

My throttle is snappier than the 04 unit. now with my Loops/Daytona mufflers it is one sweet set up now.

I agree with Rocky...my '13 F6B...with the Torq Loops and Daytona mufflers is one sweet set up. Zoom Zoom....Vrooooooom.

[WIMPY]

If you are a throttle whacker you will not notice the stumble as bad. Only hope we have in getting this fixed is by filing a claim to US DOT NHTSA. I went thur Honda with no help.

[jmohme]

And it is with great respect, and I say this very politely...I disagree. I think all those "great minds" are over thinkiing this issue, and spending unnecessary money, when the most common denominator is a much less costly repair. But...I have voiced my opinion on this matter before, and of those that have listened...the vast majority have resolved their bike stumble. Not 100 % of the bikes have been fixed, but enough to show it is a leading factor in causing the stumbling. Personally, I think the ECU/ECM is a bunch of hogwash (something that should be used to clean an Electra Glide) (humor intended), but....ultimately each of us gets to spend our money the way we each choose to.

The bottomline for me is...I sincerely hope that each and every Wing out there gets the stumble issue resolved...peacefully, and at a cost that is not too negative to the bike's owner.

I am in agreement with you on this. I really feel that there is something simple like possibly a sensor out of range that is causing this.
Fattening the fuel on the bottom of the curve may be just an attempt to compensate for output from the ECM in response to incorrect data into it.

I am not apposed to the reflash project by any means. If it nets better performance or fuel economy, thats great. But I would really rather see the root cause of the stumble determined and corrected from there. And if it is determined that it is a flaw in the programing, then the data will be in hand to correctly alter it to correct the issue.

I went through several instances like this type of hard to diagnose problems when I worked in heavy truck dealerships. There were times where a new ECM data file was the fix. but there were others where it was not.
As an example one of the OEMs that I supported. had a bad run of intake manifold temperature sensors. The sensors worked and did not log a fault, but the data these sensors sent to the ECM was incorrect once the engine reached operating temperature. This resulted in incorrect injection timing. The trucks ran poorly and smoked. We found the problem when we monitored the engine parameters with diagnostic software and verified the data on the laptop screen manually. In this case when we checked manifold temp with an temp gun. we found that the sensor data was enough lower than actual and causing the problem.

I just don't like band aid fixes. Find the cause and correct the problem.

[glarson3]

I am in agreement with you on this. I really feel that there is something simple like possibly a sensor out of range that is causing this.
Fattening the fuel on the bottom of the curve may be just an attempt to compensate for output from the ECM in response to incorrect data into it.

I am not apposed to the reflash project by any means. If it nets better performance or fuel economy, thats great. But I would really rather see the root cause of the stumble determined and corrected from there. And if it is determined that it is a flaw in the programing, then the data will be in hand to correctly alter it to correct the issue.

I went through several instances like this type of hard to diagnose problems when I worked in heavy truck dealerships. There were times where a new ECM data file was the fix. but there were others where it was not.
As an example one of the OEMs that I supported. had a bad run of intake manifold temperature sensors. The sensors worked and did not log a fault, but the data these sensors sent to the ECM was incorrect once the engine reached operating temperature. This resulted in incorrect injection timing. The trucks ran poorly and smoked. We found the problem when we monitored the engine parameters with diagnostic software and verified the data on the laptop screen manually. In this case when we checked manifold temp with an temp gun. we found that the sensor data was enough lower than actual and causing the problem.

I just don't like band aid fixes. Find the cause and correct the problem.

I can't disagree with you. If just making sure the bike was at normal operating temperature solved it, I would just deal with the need to get the bike to operating temperature, and rest easy that the problem wouldn't occur. Unfortunately, I experience the issue even when the bike is well into normal operating temperature if the bike has been sitting for 15-20 minutes. It sounds like the stumble still isn't completely solved via a re-flash, and it also has negative impact on mileage. I would sure hope it was as simple as replacing a sensor, but I want to solve the issue, not go through multiple iterations trying to find the problem. I appreciate those who have gone through the re-flash and reported their results.

[bbalzer]

Still just lucky I guess. 2012 with 60,000 miles and can't even imagine what you guys must be feeling. Sure isn't anything dangerous at all with how mine handles cold or warm. The throttle doesn't seem silky smooth if idling around a corner and then accelerate, but sure doesn't stumble or hesitate at all. Does accelerate a little jerky but it is more of a slight jump, not falter. Have never felt this. Maybe you should run gas with 10% ethanol added. :-) that's what mine has seen the most.

[cmock]

I typically use non-ethanol in my bikes(especially my old carbed one) but i ran my 14 wing on ethanol for one week and nothing changed except a drop in fuel mileage and a slight drop in power. On non-eth i get 41-46 mpg. (I drive 48 miles to work and 48 home at 60mph), and when i changed over to ethanol it dropped to 36-38 mpg.(same speed) Now if i run at 65-70 mph with non eth i get 36-38 mpg.(RPM /needs 6th gear for better mileage)

[530ktm]

I can't disagree with you. If just making sure the bike was at normal operating temperature solved it, I would just deal with the need to get the bike to operating temperature, and rest easy that the problem wouldn't occur. Unfortunately, I experience the issue even when the bike is well into normal operating temperature if the bike has been sitting for 15-20 minutes. It sounds like the stumble still isn't completely solved via a re-flash, and it also has negative impact on mileage. I would sure hope it was as simple as replacing a sensor, but I want to solve the issue, not go through multiple iterations trying to find the problem. I appreciate those who have gone through the re-flash and reported their results.

Sounds to me like it is some type of sensor that cools down enough after sitting for 15 or 20 minutes to make the stumble act up again. I have never experienced this stumble the way you are describing and hopefully I never do.

[lyle doverspike]

I can't disagree with you. If just making sure the bike was at normal operating temperature solved it, I would just deal with the need to get the bike to operating temperature, and rest easy that the problem wouldn't occur. Unfortunately, I experience the issue even when the bike is well into normal operating temperature if the bike has been sitting for 15-20 minutes. It sounds like the stumble still isn't completely solved via a re-flash, and it also has negative impact on mileage. I would sure hope it was as simple as replacing a sensor, but I want to solve the issue, not go through multiple iterations trying to find the problem. I appreciate those who have gone through the re-flash and reported their results.

My bike does the same thing after riding at normal temp for an hour, and it is shut off for 15 to 20 minutes, upon starting it will stumble after a minute or two. 2012 bike, 59,000 miles on third set of NGK stock plugs.

[glarson3]

I'm going to try to get a video of this stumble so that people can see it happen. I know this is an issue that is hard to wrap your head around if you've never experienced it. It's mostly scary if I'm pulling out into traffic and don't know if it's going to happen. The quickest way to recover when it stumbles is to get into the friction zone where a quick increase in throttle input won't have a significant impact on speed. The problem with this solution is you're sitting out in traffic hoping you can recover safely before becoming a speed bump.

I can say with 100% certainty the issue is not the brakes, though it's fair to suspect them with two brake recalls so far.

I can duplicate the stumble in neutral, so it's definitely something to do with air/fuel delivery.

[cmock]

I mentioned this on cruiesmans comment, but i wonder if some of it is temp related. Because now that our temps are dropping upper 40s most mornings and some 30s my bike dosnt stumble at all. Now when it was warm out it would stumble only when bike was cool and would not do it again once bike was warm. It looks to me like everyone who experiences this stumble has a slightly different situation with it. But the one thing that stays static is the rpm and general speed it happens at. It makes me think this may even be a tps(throttle position sensor) issue or similar. Im not incline to think its the ecu/m anymore.

[harvey]

I can duplicate the stumble in neutral, so it's definitely something to do with air/fuel delivery.

I think you forgot to include the part ignition may play. Suppose just for a few seconds there is no spark to ignite the air/fuel mixture. I do agree that something is wrong in one or more of the delivery systems, I just wish I had the knowledge to find the problem and then the solution.

[glarson3]

I think you forgot to include the part ignition may play. Suppose just for a few seconds there is no spark to ignite the air/fuel mixture. I do agree that something is wrong in one or more of the delivery systems, I just wish I had the knowledge to find the problem and then the solution.

I'm in the same boat as you. I don't understand enough of the inner workings of all of the factors, and the best method to rule out one particular component.

[jmohme]

These types of problems can be very difficult to troubleshoot even when you do understand the systems, how they work, and the diagnostic tools.

In the trucking business, we had software that allowed us to monitor every parameter and sensor while driving the truck, and even with that, you sometimes came back scratching your head. Problems like a stumble can happen so fast that they are over before a fault can even be logged. It was times like those when I would have to have someone drive me around while I monitored the laptop and sometimes several meters and an oscilloscope to catch the problem as it happened.

[biglefti]

And it is with great respect, and I say this very politely...I disagree. I think all those "great minds" are over thinkiing this issue, and spending unnecessary money, when the most common denominator is a much less costly repair. But...I have voiced my opinion on this matter before, and of those that have listened...the vast majority have resolved their bike stumble. Not 100 % of the bikes have been fixed, but enough to show it is a leading factor in causing the stumbling. Personally, I think the ECU/ECM is a bunch of hogwash (something that should be used to clean an Electra Glide) (humor intended), but....ultimately each of us gets to spend our money the way we each choose to.

The bottomline for me is...I sincerely hope that each and every Wing out there gets the stumble issue resolved...peacefully, and at a cost that is not too negative to the bike's owner.

I've not been able to find the post that shows what you think is the problem. Do you mind re-directing me to it?

[srt8-in-largo]

These types of problems can be very difficult to troubleshoot even when you do understand the systems, how they work, and the diagnostic tools.

In the trucking business, we had software that allowed us to monitor every parameter and sensor while driving the truck, and even with that, you sometimes came back scratching your head. Problems like a stumble can happen so fast that they are over before a fault can even be logged. It was times like those when I would have to have someone drive me around while I monitored the laptop and sometimes several meters and an oscilloscope to catch the problem as it happened.

What monitoring tools can be used on the GL1800? In my car I tap into the OBD II port and have a tool that logs everything I need... engine temp, oil temp, intake air temp, fuel pulse width, throttle position, engine knock, manifold pressure, etc, etc.

Why has the Stumble had so much conversation... but so little apparent effort among users to try to capture data for analysis?

[cmock]

Ive never actually seen a diag. devise for motorcycle(Goldwing) computers. I can go to any auto store and get one for my car but have never seen one for a bike. Also Honda seems to deny this is even a problem. I was told by dealer this is a cold running issue. That is if it were a carbed engine it would not be drivable. In my case it only does this when cool and now is starting to decrease in frequency. Hasnt happend in a while. Took bike out today for the first time in a day and a half and didnt even let it warm up very much and did not stumble. Everybody seems to have a different experience with the stumble.