(SOLVED) Idle Stepper Readings

[Wallace J Gingerich]

I'm in the process of tracking down an episodic high idle on my 2007 Norge with 48,000 miles and trying to check to see if the idle stepper motor is working as it is supposed to. Only problem is I don't know for sure what the various idle stepper readings (base, break, and controller) refer to and what their values should be if the stepper is working correctly.

Here are some readings I've jotted down:

(stepper base, stepper break, stepper controller)
engine cold at idle 100 170 70
engine warm, off idle 100 100 0
engine warm at idle 100 50 206

What do "base", "break" and "controller" refer to?
Are these readings consistent with a properly functioning stepper motor?

The stepper motor never shuts off air flow completely -- it flows air to the throttle bodies (as evidenced by a vacuum in the hose running to the air box) at all of the settings noted above, the higher the break reading the more air. Is this normal? If not, what should the various readings be at idle when the stepper is functioning normally?

Today (outside temp around freezing) the bike idled around 1300 after completely warmed up, with the break reading 50 and the controller 206. When I plugged the hose from the air box to the stepper the idle dropped to 1200.

I'll probably end up inserting a cutoff between the air box and the stepper motor as others have done, but I'm curious about the stepper motor readings.

Has anyone identified an alternative stepper motor that would work on the Norge?

 

[kiwi dave]

I'll probably end up inserting a cutoff between the air box and the stepper motor as others have done.....

That's what I've done on all my 1200 Sports. The added bonus is the increased engine braking that is achieved when the feed from the stepper motor is turned off.

 

[john zibell]

Best recommendation is to clean the stepper. You will find information on how to do this on this site.

 

[scottmastrocinque]

Wallace, please... do yourself a favor and forget the Diag. You do not need to cut the stepper motor off.

Like many people I have encountered that have used that thing, you are looking for problems, which are not software related, but rather a result of simple needed physical maintenance!

Worrying about this value and that value is a worthless undertaking from the start especially for something as well sorted out by the Moto Guzzi factory as the steeper motor.

Think of your steeper motor as a variable air needle jet which controls the flow of additional air into the intake. It is a very small orifice and sensitive to contamination, gumming up, and varnishing.

Attempting to alter the factory settings on the software for the steeper motor, is a recipe for disaster.

The stepper motor works exactly like it was designed to do, provided that it is periodically cleaned, you do not overfill your crankcase oil and cause excess oil to be blown up into the airbox, and you replace the air filter on a schedule to maintain good clean and consistent air flow. Thankfully, the procedure to clean it is so simple.

On my 2008 1200 Sport I recently acquired, the idle was occasionally erratic. I used some long reach hose grip pliers from Harbor Freight Tools (a truly amazing and useful set of [3] tool), to quickly detach the stepper hose from the airbox.

Precisely as John Zibell has written on other posts here on the forum, I started the bike and squirted carburetor cleaner directly into the hose while manually raising the idle to keep the bike from stalling out. A few squirts of cleaner down the pipe, and "Voila!", idle issue solved immediately, simply, cheaply, with little to no stress.

The hose grip pliers made the job so simple. I used the same tool to replace the hose onto the airbox nipple and press it up all the way back into place. In the case of the 1200 Sport, I didn't even need to remove any bodywork. I could simply slide it in to the correct position from the right hand side of the motorcycle.

My 1200 Sport has a perfect idle ever since. Clean your steeper motor and yours will too. I'd bet on it.

I hope this helps.

 

[GuzziMoto]

I agree with Dave, install a valve to turn it off. That said, you may need to clean it to get it working properly. But even a properly working stepper motor I would want the ability to turn off. Once the bike is warmed up and idling properly turning the stepper off increases compression / engine braking and the throttle response during shifts is cleaner and crisper, making shifts feel better.

 

[V700Steve]

The early steppers are metal, lots have problems. Then it was changed to a plastic one that doesn't fail. Hey, they were cheap when they came out($125). Still too much for cheap asses. Should have got one in 2010 for that price. Last checked in 16 was around $250. NOW, get this, it's $721. Better get one before they are a grand. Same part went from 125 to over 700.

 

[Wallace J Gingerich]

A bit more background -- I have thoroughly cleaned the TBs and stepper motor, and associated hoses and passage ways (removed from bike) with carb cleaner. There was no oil in the air box. I meticulously synced the TBs. The valves are adjusted to spec. Still there is occasional high idling.

I do NOT plan to modify the stepper motor or the CPU map in any way. I am mainly interested in learning more about the stepper motor and how it operates.

Does anyone know what the three stepper readouts on Diag (base, controller, break) refer to, and what the values should be for a properly functioning stepper motor?

 

[M0T0Geezer]

I too have fast-idle problems with my 2007 Norge (2-valve heads). I am still fighting the battle to fix it, but at least somewhere within all the comments here and elsewhere I am certain the cure is there.

I have gathered these and more in this on-line collection of URLs on the general subject of Guzzi "large block" bikes:

dansher.com/bikepix/Guzzi/Norge1200/Norge_2007_fyi.txt

 

[Kevin.NZ]

I cleaned out the ball/socket linkage as there was muck causing idle issues.

 

[Trout]

One other thing to check is wiring, especially grounds & proper batt voltage.

Victory's are especially prone to high idle if battery is low or terminals are loose.
Todays computers are very sensitive current wise.

 

[scottmastrocinque]

Thanks for all the suggestions. After cleaning the TBs, stepper motor, syncing the TBs, etc., etc., I think I have solved the sporadic high idle problem - more riding when the weather breaks will confirm it (or not).

.... but I'd still like to know what the stepper motor readings on the various software programs refer to, and what normal values should be. I believe the VDSTS program uses the terms initial, closed loop, and Delta reg. for the stepper motor readouts.

Anyone happen to know?

Nobody will know. Moto Guzzi does not publish or release this information.

 

[scottmastrocinque]

A bit more background -- I have thoroughly cleaned the TBs and stepper motor, and associated hoses and passage ways (removed from bike) with carb cleaner. There was no oil in the air box. I meticulously synced the TBs. The valves are adjusted to spec. Still there is occasional high idling.

I do NOT plan to modify the stepper motor or the CPU map in any way. I am mainly interested in learning more about the stepper motor and how it operates.

Does anyone know what the three stepper readouts on GuzziDiag (base, controller, break) refer to, and what the values should be for a properly functioning stepper motor?

Which side is your air bypass on the throttle body open on? More specifically, you said you balanced the throttle bodies. I want to confirm that the air bypass is open on one side only.

 

[Wallace J Gingerich]

I balanced the TBs (using the bell crank on left TB) at 3500 RPM with both air bypass screws closed. Then I reset TPS. Then I balanced the TBs at idle (1200 RPM) by opening the left bypass screw by about a quarter turn.

 

[scottmastrocinque]

I balanced the TBs (using the bell crank on left TB) at 3500 RPM with both air bypass screws closed. Then I reset TPS. Then I balanced the TBs at idle (1200 RPM) by opening the left bypass screw by about a quarter turn.

I assume what you mean by “bell crank” is the adjustment screw.

Although I wrote this for the Stelvio, the process is the same.

https://www.guzzitech.com/forums/threads/syncing-throttle-bodies-stelvio-8v.9082/page-2

If you only opened 1 bypass screw on the higher registering side, thereby lowering the manifold vacuum, that would be correct.

I’m trying to wrap my head around the intermittent idle variance.

Hmm...

Have you tried spraying cleaner around all the vacuum lines and associated fittings to see if idle changes due to a unseen crack or leak?

Does the bike still have the evaporative canister still installed and connected to the intake?

 

[Wallace J Gingerich]

Yes, by bell crank I mean the adjusting screw on the left end of the connecting rod.

Yes, spraying carb cleaner around TBs and intake manifolds showed no air leaks.

Today I sprayed silicone lube into the stepper motor and cycled it a few times (ignition on/off). That, and perhaps the repeated use of the stepper motor since
cleaning if it, may have taken care of the erratic high idle problem. On a ride today the problem didn't show itself.

 

[scottmastrocinque]

Yes, by bell crank I mean the adjusting screw on the left end of the connecting rod.

Yes, spraying carb cleaner around TBs and intake manifolds showed no air leaks.

Today I sprayed silicone lube into the stepper motor and cycled it a few times (ignition on/off). That, and perhaps the repeated use of the stepper motor since
cleaning if it, may have taken care of the erratic high idle problem. On a ride today the problem didn't show itself.

This is excellent news. Congratulations.

I have to be honest with you though. It may be the fact that it is texts, and your tone and disposition isn’t readily available, but I clearly received the message that you seem to me to have been very curt, and unreceptive to honest attempts to help you. You come off as above it all and dismissive. This is my sincere take on the discussion.

You were politely told straight up that the software you were using is not supported here, yet you continued hammering away at it. You were given the correct and ultimate solution by more than one person yet never acknowledged the assistance or the fact that it worked in solving your problem.

May I suggest professor, that you work on a little humility, receptivity and some modicum of gratitude towards total strangers that you seek assistance from. You will probably find more people might be willing to jump in and help you.

Anyway, best of luck with your Moto Guzzi.

 

[GuzziMoto]

I did not take any issues with what you said / posted. Just my two cents.
I am glad yours seems to be working. Let me know if you want to come over to the dark side and put in a valve to turn the stepper off. You can test the idea to see if you like it by pinching off the line between the stepper and the airbox.
All good by me.

 

[Wallace J Gingerich]

This is excellent news. Congratulations. I have to be honest with you though. It may be the fact that it is texts, and your tone and disposition isn’t readily available, but I clearly received the message that you seem to me to have been very curt, and unreceptive to honest attempts to help you. You come off as above it all and dismissive. This is my sincer

scottmastrocinque, thanks for your honest feedback. I was hoping to get some help with how the stepper motor functions, what the values on diagnostic software refer to, and what the values should be in normal operation. I didn't get any responses directly related to that, and I was growing frustrated. I did try to respond to members' questions and suggestions about solving the high idle problem, but I was indeed brief on this because it was not what I was most interested in. Perhaps I didn't make myself clear enough on what I was looking for, and perhaps I did not show enough appreciation for members' suggestions, and for that I apologize. But since folks still responded here I wanted to respond.

So, thanks to all for sharing your thoughts and suggestions. I believe I may have the idle problem solved with repeated use of the stepper motor following thorough cleaning of it and the TBs, lubing the stepper motor with silicone, and an anal sync of the TBs. The bike now idles at 1200, and a relatively brief ride didn't show any problems with high idle. I'm still interested if anyone has knowledge of the stepper motor readings.

Forums like this one are of immense value to me, an avid do-it-yourselfer who who has no training or formal experience in motorcycle maintenance, but has an insatiable interest in learning how they work and diagnosing and fixing problem like this one.

All the best....

 

[Wallace J Gingerich]

To round out the discussion of idle stepper readings a little more, I think I've "cracked the code." What follows is my best guess - not established fact. (I'm using Diag but I'm confident VDST provides the same readings, albeit using different labels.)

What Diag calls stepper idle break refers to the "step" the motor is on (stepper motors turn their shafts in precise steps), which regulates the amount of air to flow to the TBs, more air at higher steps and less at lower steps -- only Moto Guzzi know the precise amount. I have observed readings as high as 170 when the engine is cold and as low as 50 when the engine is fully warmed up.

Stepper motor base always reads 100, and I think that is the reference point for calculating break values and/or it is where the motor sits when it is not activated.

Stepper controller values appear to be instructions from the ECU to tell the stepper which step to move to. For idle break values above 100 the desired break value is the controller value plus 100 (e.g., controller value of 30 tells the motor to go to step 130). For idle break values less than 100, the desired break value is the controller values minus 156 (e.g., a controller value of 206 results in a break value of 50).

My experience suggests that a break reading of 50 is normal for fully warmed up motor. I'm hoping this information will be useful for members who would like to know if their stepper motor is operating normally.

 

[Wallace J Gingerich]

In the process of reviewing this thread, I mistakenly deleted the post I made on Nov 13 or 14 which scottmastrocinque quotes in full in post #11. My sincere apologies - I thought it was a duplicate, but not!