Author Topic: Does anyone know why my bike is doing this?  (Read 1716 times)

Offline vitsiozo

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Does anyone know why my bike is doing this?
« on: June 28, 2022, 12:58:24 PM »
Hi, I got a V7 Special 2013 model. I have had an issue a couple of years ago where when starting the bike, it would rev on its own and then not be able to idle properly. This was an intermittent issue (only really happened a couple of times) but on the occasions that it happened it made it very difficult to drive the bike around.
Subsequently I checked the fuelling map that was used on the bike and saw that it was the original version that came with the bike and no update had been made since. I kinda suspected that the fuelling of the bike could be the issue so I took the dive and installed a custom Beetlemap that would also accommodate the after market exhausts I had on the bike. I thought I was done with the problem as for over a year the bike ran without a hiccup.

Just today however the issue re-emerged! I took the bike out for a ride, all was smooth, parked somewhere for a coffee, then came out, started her up and this happened:

https://youtube.com/shorts/q1borOqMAiY?feature=share

Upon starting the bike it revs hard for a while and then cannot settle at idle speed but goes up and down, up and down. Very difficult to control the throttle and the bike switches off easily. The bike was dry as the weather is nice at the moment.

Has anyone seen this behaviour and have any inkling as what might be behind this?

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Re: Does anyone know why my bike is doing this?
« Reply #1 on: June 28, 2022, 01:03:49 PM »
Throttle cables properly routed and not pinched?

Perhaps a gas tank pressure issue--Have you tried 'burping' the gas tank--open the cap, see if the tank has any vacuum due to changes in atmospheric pressure?
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Offline vintagehoarder

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Re: Does anyone know why my bike is doing this?
« Reply #2 on: June 28, 2022, 01:15:24 PM »
13-14's had an issue with the spark plug caps, our 14 did the smae thing.  Changed them out not an issue since. I am sure there is a thread on here about it, as somone gave me the number back then of the cap I needed.  Maybe someone more educated than I will jump in here.  I think  this was an official recall at the time, check with your dealer.


Try this thread.....

https://wildguzzi.com/forum/index.php?topic=96129.0
« Last Edit: June 28, 2022, 01:17:52 PM by vintagehoarder »
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Re: Does anyone know why my bike is doing this?
« Reply #3 on: June 28, 2022, 01:30:45 PM »
Start the bike at night and look for the sparks.  When was the last time you checked the plugs for an indication of the fueling?  Italian tune-up needed.  Your riding is mostly in town?  What rpm's do you shift at?
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Re: Does anyone know why my bike is doing this?
« Reply #3 on: June 28, 2022, 01:30:45 PM »

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Re: Does anyone know why my bike is doing this?
« Reply #4 on: June 28, 2022, 02:38:36 PM »
Does your bike have a stepper motor that controls the idle ?

Offline vitsiozo

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Re: Does anyone know why my bike is doing this?
« Reply #5 on: June 28, 2022, 03:44:08 PM »
Hi, thanks for taking the time to reply to me.
Just to answer a few of the points, don't think it's a problem with the throttle cables, properly routed and not pinched. I can check the gas tank to see if this makes any difference even though the idling ups and downs are very periodic, so I can't imagine how pressure could do this.

I am definitely going to check the threads for the spark plug caps and also check the spark plugs themselves tomorrow for any indications.
I don't quite understand what you mean Tom by saying to check for sparks at night.. what am I looking at? Also what is an Italian tune-up? Yes, riding is mostly in town but I take her occasionally out of town for a good stretch where I take her much higher in revs.

Huzo, no the bike does not have a step motor as far as I know.

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Re: Does anyone know why my bike is doing this?
« Reply #6 on: June 28, 2022, 04:03:38 PM »
‘13-‘14’s had a cold start issue.  Somewhat corrected by an updated factory map, but not 100%.  Gotta let it warm up for a few minutes before taking off.  Wasn’t a big deal for me cause I’m used to old carbed bikes. 
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Offline Frenchfrog

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Re: Does anyone know why my bike is doing this?
« Reply #7 on: June 28, 2022, 04:10:37 PM »
By checking the sparks at night he means that in the dark you should easily be able to see any showing up which means the cap  insulation is failing an they are shorting out.

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Re: Does anyone know why my bike is doing this?
« Reply #8 on: June 28, 2022, 05:15:51 PM »

Huzo, no the bike does not have a step motor as far as I know.

It must, at it needs some method of controlling idle air. I presume it is another unserviceable component of the combination ECU/throttle body.
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Offline lucky phil

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Re: Does anyone know why my bike is doing this?
« Reply #9 on: June 28, 2022, 05:27:25 PM »
It must, at it needs some method of controlling idle air. I presume it is another unserviceable component of the combination ECU/throttle body.

V11's and many Guzzis run just fine with IFE and no stepper motor as do many many Ducati's with EFI. They use air bypass screws and throttle plate stops working in concert for idle control together with fuel and ignition mapping of course. Not sure what the OPs bike uses but if it does use a stepper motor that would be a good place to start looking. Electrical connection first I'd suggest.

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Offline rtbickel

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Re: Does anyone know why my bike is doing this?
« Reply #10 on: June 28, 2022, 05:34:04 PM »
Vitsioso, an Italian tune-up means to flog the bike for all it is worth in order to blow the carbon off the pistons, plugs & valves.  Also, most satisfying and can be performed with any vehicle.
« Last Edit: June 28, 2022, 05:35:55 PM by rtbickel »
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Re: Does anyone know why my bike is doing this?
« Reply #11 on: June 28, 2022, 05:48:49 PM »
If it was a car it would be the ecu searching for the signal from the Ox sensor on the exhaust.  Usually the sensor is gone and the ecu is searching to add then take out on the fuel.  Ox sensors get dirty or wear out.

1st & 2nd gear in town.  Maybe once in awhile 3rd gear but only on longer straights.  Otherwise too low on the rpm's in town.  Check your spark plugs.
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Re: Does anyone know why my bike is doing this?
« Reply #12 on: June 28, 2022, 07:15:16 PM »
You obviously have the cable with ability to load a map via guzzi diag or other software. plug the bike in and check for fault codes, My guess is you have a bad sensor , as Tom mentioned, sounds like a bad signal from an o2 sensor or possibly the  temp sensor. Either should  show a code in diagnostics. Another thing to check is your air filter to make sure it is not oil saturated .

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Re: Does anyone know why my bike is doing this?
« Reply #13 on: June 28, 2022, 08:17:30 PM »
V11's and many Guzzis run just fine with IFE and no stepper motor as do many many Ducati's with EFI. They use air bypass screws and throttle plate stops working in concert for idle control together with fuel and ignition mapping of course. Not sure what the OPs bike uses but if it does use a stepper motor that would be a good place to start looking. Electrical connection first I'd suggest.

Phil

Can't speak the V11 sports, obviously the Cali V11's and the 2 TB smallblocks both used physical fast idle levers.

The CARCs all used steppers.

I've been told the 1TB smallblocks use a bypass valve or something integrated into the throttle body.

But no matter what the solution the ECU can't automatically adjust idle speed unless it has some method of controlling air right?

Bypass screws or whatnot are fine if they are adjusted and set for certain conditions, but what happens on other conditions? And there are no physical adjustments on the 1TB units.

Oh screw this... See link, download PDF, SEE PAGE 7, Stepper Motor:

https://www.guzzitek.org/documents/injection/ECU_MIU-G3_Training.pdf


Ha ha sorry got tired going from memory...
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Offline CoolBreezeBreva

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Re: Does anyone know why my bike is doing this?
« Reply #14 on: June 28, 2022, 09:10:23 PM »
Check fuses?

Offline lucky phil

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Re: Does anyone know why my bike is doing this?
« Reply #15 on: June 29, 2022, 01:07:59 AM »
Can't speak the V11 sports, obviously the Cali V11's and the 2 TB smallblocks both used physical fast idle levers.

The CARCs all used steppers.

I've been told the 1TB smallblocks use a bypass valve or something integrated into the throttle body.

But no matter what the solution the ECU can't automatically adjust idle speed unless it has some method of controlling air right?

Bypass screws or whatnot are fine if they are adjusted and set for certain conditions, but what happens on other conditions? And there are no physical adjustments on the 1TB units.

Oh screw this... See link, download PDF, SEE PAGE 7, Stepper Motor:

https://www.guzzitek.org/documents/injection/ECU_MIU-G3_Training.pdf


Ha ha sorry got tired going from memory...

Yep and so does the V11 Sport and the Daytona and Centauro. The point I was making is many older EFI engines control the idle without a stepper motor so it's not a mandatory thing to have. When the engine is cold you can use the fast idle lever or the throttle to maintain an elevated rpm for warm up. My V10 Sport starts and idles without the fast idle lever or throttle at any temps from 10 deg C to 40 deg C. Then again it's been mapped by me not the factory.

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Re: Does anyone know why my bike is doing this?
« Reply #16 on: June 29, 2022, 04:16:02 AM »
Yep and so does the V11 Sport and the Daytona and Centauro. The point I was making is many older EFI engines control the idle without a stepper motor so it's not a mandatory thing to have. When the engine is cold you can use the fast idle lever or the throttle to maintain an elevated rpm for warm up. My V10 Sport starts and idles without the fast idle lever or throttle at any temps from 10 deg C to 40 deg C. Then again it's been mapped by me not the factory.

Ciao

 :thumb:

Ahhh, ok I see where you're going. But it's not in conflict with my logic. An ECU cannot control cold and hot idle speed without something like a stepper/bypass. Now maybe there's an exception somewhere that uses say ignition timing or something to affect idle speed.

But absent an automatic/ECU controlled system there's a mechanical method that's adjustable. I knew the 1TB didn't have that and seemed to "control" idle speeds therefore there has to be a mechanism.

Your lack of need got the fast idle lever for cold streets suggests richer mapping and probably idle speeds that vary somewhat from spec (neither of which are necessarily problematic). EFI does have an advantage over carburetors here in that it can enrichen mixture for cold starts without needing to mechanically limit air for the same result or open an additional fuel passage etc. But it still doesn't actively control the speed without additional input if that makes sense.

Anyway op, let us know what you find.
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Offline lucky phil

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Re: Does anyone know why my bike is doing this?
« Reply #17 on: June 29, 2022, 04:29:51 AM »
:thumb:

Ahhh, ok I see where you're going. But it's not in conflict with my logic. An ECU cannot control cold and hot idle speed without something like a stepper/bypass. Now maybe there's an exception somewhere that uses say ignition timing or something to affect idle speed.

But absent an automatic/ECU controlled system there's a mechanical method that's adjustable. I knew the 1TB didn't have that and seemed to "control" idle speeds therefore there has to be a mechanism.

Your lack of need got the fast idle lever for cold streets suggests richer mapping and probably idle speeds that vary somewhat from spec (neither of which are necessarily problematic). EFI does have an advantage over carburetors here in that it can enrichen mixture for cold starts without needing to mechanically limit air for the same result or open an additional fuel passage etc. But it still doesn't actively control the speed without additional input if that makes sense.

Anyway op, let us know what you find.

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The 15M,15RC,16M ecu has cold enrichment that trims the fuel injector duration with regards to inlet temp and engine temp. So obviously in low OAT and engine temps you get more fuel. On top of that there is cranking enrichment which also adds even more fuel for the first 4000 engines revolutions after starting which tapers off to zero trim after 4000 revolutions have occurred. Paradoxically this enrichment trim happens every time the engine is started irrespective of the engine temp. My engine will idle when cold without throttle input, a little low and erratic until it gets some heat into the heads which helps the fuel vaporise but it doesn't stall.

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« Last Edit: June 29, 2022, 04:30:10 AM by lucky phil »
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Offline vitsiozo

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Re: Does anyone know why my bike is doing this?
« Reply #18 on: July 06, 2022, 08:02:49 AM »
Hi and thanks for all your replies. I am sorry I cannot contribute to the stepper motor question as my knowledge is very limited on this, I just did not find any mention of such thing in the manual and assumed the bike does not come with one.

Coming back to the issue however, I think that @vintagehoarder must have had the point. I removed spark plug caps and spark plugs this morning for inspection. I am attaching the images of each. There is a significant difference in how they look. It's the left hand side cylinder which looks much more black/oxidised. More interestingly however is the fact that upon reassembly and starting up the bike again the spluttering, inconsistent idling and cut-offs have now gone.

So I am probably looking at an intermittent problem caused by the spark plug cables ...



 I will try to search this forum for information about problems with this year models and see what I can find.

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Re: Does anyone know why my bike is doing this?
« Reply #19 on: July 06, 2022, 08:33:45 AM »
Hi and thanks for all your replies. I am sorry I cannot contribute to the stepper motor question as my knowledge is very limited on this, I just did not find any mention of such thing in the manual and assumed the bike does not come with one.

Coming back to the issue however, I think that @vintagehoarder must have had the point. I removed spark plug caps and spark plugs this morning for inspection. I am attaching the images of each. There is a significant difference in how they look. It's the left hand side cylinder which looks much more black/oxidised. More interestingly however is the fact that upon reassembly and starting up the bike again the spluttering, inconsistent idling and cut-offs have now gone.

So I am probably looking at an intermittent problem caused by the spark plug cables ...



 I will try to search this forum for information about problems with this year models and see what I can find.

Fingers crossed.

I probably should have said at the start that I have had the unstable idle on cold starts since I purchased my Stone new in Dec 2012.

I had the factory map updated - no help.

I didn't do a Beetle map because that was (and remains) literally my only problem.

I don't THINK changing the spark plug caps changed anything (I ran the OEM ones till sometime in the last year). But the symptoms seem to vary with ambient temperature and humidity so that could have something to do with it in my (or our cases).

I don't know that I've ever had the high-rev thing happen, though now it makes me wonder if that's occasionally caused by the ECU attempting to compensate for the idle stumbles. < shrug >

I will say that I get why an intermittent cylinder misfire might cause an occasional stumble, but I don't think that has anything to do with the cold start stumble.

But again fingers crossed...
« Last Edit: July 15, 2022, 06:12:53 AM by Kev m »
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Re: Does anyone know why my bike is doing this?
« Reply #20 on: July 06, 2022, 08:38:03 AM »
So I am probably looking at an intermittent problem caused by the spark plug cables ...



 I will try to search this forum for information about problems with this year models and see what I can find.

2013 is a single throttle body, right? Any chance the one cylinder's injectors are clogged to show such a difference in spark plugs, or maybe the plug gaps aren't set? Am I showing my lack of experience/knowledge?
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Re: Does anyone know why my bike is doing this?
« Reply #21 on: July 06, 2022, 06:09:03 PM »
Those plug gaps both look big in the photos . did you re gap them before re installing? I think .027 is recommended.

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Re: Does anyone know why my bike is doing this?
« Reply #22 on: July 06, 2022, 08:16:05 PM »
Those plug gaps both look big in the photos . did you re gap them before re installing? I think .027 is recommended.
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Offline lucky phil

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Re: Does anyone know why my bike is doing this?
« Reply #23 on: July 07, 2022, 02:27:54 AM »
Those plug gaps both look big in the photos . did you re gap them before re installing? I think .027 is recommended.

Compared to the thread pitch the gaps look reasonable to me. They need to be wrong by a lot usually to create issues. The plugs do however look worn without a nice sharp edge on the centre electrode. They should be replaced. Probably wont help the issue but they need replacing anyway.

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Offline vitsiozo

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Re: Does anyone know why my bike is doing this?
« Reply #24 on: July 15, 2022, 05:51:11 AM »
Thanks for all the good advice.

I will be first of all changing the spark plugs. If you look close at the image below, there is a black residue/banding on the top of the spark plug where it connects to the plug cable. I wonder if this might be affecting the connection under certain temp/humidity settings thus causing the problem.
I will not be going down the route of changing plug cables at this stage.

 



I do however wonder as some of the posts here suggest, whether I have to personally adjust the plug gaps on the new spark plugs I receive ??
I mean, first of all I would not know how to do this and secondly I would assume that one of the numbers in the spark plug name (NGK CPR8EB-9 in this case), refers to the gap the plugs come with. Is it really the case that Moto Guzzi expects the owners to adjust the gap of the spark plugs when replacing them with the same exact model as OEM?

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Re: Does anyone know why my bike is doing this?
« Reply #25 on: July 15, 2022, 06:18:48 AM »
Thanks for all the good advice.

I will be first of all changing the spark plugs. If you look close at the image below, there is a black residue/banding on the top of the spark plug where it connects to the plug cable. I wonder if this might be affecting the connection under certain temp/humidity settings thus causing the problem.
I will not be going down the route of changing plug cables at this stage.

 



I do however wonder as some of the posts here suggest, whether I have to personally adjust the plug gaps on the new spark plugs I receive ??
I mean, first of all I would not know how to do this and secondly I would assume that one of the numbers in the spark plug name (NGK CPR8EB-9 in this case), refers to the gap the plugs come with. Is it really the case that Moto Guzzi expects the owners to adjust the gap of the spark plugs when replacing them with the same exact model as OEM?

Lots of nope here.

As I've said, my 2013 has done this since new, with the original map, with an updated OEM map, with BRAND spanking new spark plugs, with new spark plug caps... the occasional cold start stumble for a few minutes till warm is the only symptom mine has ever had and it goes away as soon as it is warmed up.

Now why yours didn't seem to do it much before, I have no idea.

No I don't think that residue means jack. But then again I really don't believe that stumble is just an ignition misfire.

As for spark plugs, no, the gap is not in the code. The code is strictly about heat range (length of insulator), thread diameter, whether it's a resister plug or not etc. Though spark plugs often will be near or close to the correct gap when purchased, they are not designed for just one motor and therefore they might be wildly wrong. A simple wire feeler gauge is used to measure the gap, and it is adjusted by very VERY gently bending the side electrode that protrudes out to vary the gap.

But fresh plugs aren't going to hurt anything.
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Offline vitsiozo

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Re: Does anyone know why my bike is doing this?
« Reply #26 on: July 15, 2022, 02:07:13 PM »
Lots of nope here.

As I've said, my 2013 has done this since new, with the original map, with an updated OEM map, with BRAND spanking new spark plugs, with new spark plug caps... the occasional cold start stumble for a few minutes till warm is the only symptom mine has ever had and it goes away as soon as it is warmed up.

Now why yours didn't seem to do it much before, I have no idea.

No I don't think that residue means jack. But then again I really don't believe that stumble is just an ignition misfire.

As for spark plugs, no, the gap is not in the code. The code is strictly about heat range (length of insulator), thread diameter, whether it's a resister plug or not etc. Though spark plugs often will be near or close to the correct gap when purchased, they are not designed for just one motor and therefore they might be wildly wrong. A simple wire feeler gauge is used to measure the gap, and it is adjusted by very VERY gently bending the side electrode that protrudes out to vary the gap.

But fresh plugs aren't going to hurt anything.

Thanks for that Kev, message received. The way I see it it will be hard for me to pinpoint the problem since this seems to only occur on very rare occasions and disappears before I have the chance to put the diagnostic tool on the bike. As I said earlier, this time the problem stopped as soon as I took out the plug cables and put them back on again. Correlation is not causation of course, so I need to see if this will be relevant next time this happens.

On with changing the spark plugs then. I measured the gap on a pair of brand new ones and they come at 0.75mm. The user's manual says gap should be 0.6mm-0.7mm, so I guess 0.65mm is what I should be aiming at, right?

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Re: Does anyone know why my bike is doing this?
« Reply #27 on: July 15, 2022, 02:10:29 PM »
Thanks for that Kev, message received. The way I see it it will be hard for me to pinpoint the problem since this seems to only occur on very rare occasions and disappears before I have the chance to put the diagnostic tool on the bike. As I said earlier, this time the problem stopped as soon as I took out the plug cables and put them back on again. Correlation is not causation of course, so I need to see if this will be relevant next time this happens.

On with changing the spark plugs then. I measured the gap on a pair of brand new ones and they come at 0.75mm. The user's manual says gap should be 0.6mm-0.7mm, so I guess 0.65mm is what I should be aiming at, right?

 :thumb:  Yup to everything. I hear ya!

If you ever really figure it out, let me know too. lol.  :boozing:

On the plug if anything I tend to gap toward the lower end of the range more than the middle. The gap will widen in use and the bigger the gap the more resistance/harder the jump.

That said, I'm sure middle of the range is fine. I don't get the impression these ignition systems are underpowered or overstressed.
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Offline centauro

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Re: Does anyone know why my bike is doing this?
« Reply #28 on: July 15, 2022, 03:46:34 PM »
I am nowhere qualified to offer any advice, since I have never owned any fuel injected bikes, but the fluctuating idle on any engine is usually associated with an air intake leak.
The ECU would then try to boost the fueling to compensate for the extra air going in. The sudden acceleration may be happening because, after parking the bike for awhile, the motor has cooled enough for the ECU to command a higher idle speed to warm up the motor. From the video, I can see that when the idle speed fluctuates, and throttle is applied, the response is very sluggish, typical of a very lean condition. The plugs appear to reflect this, as they are overly clean at the tips, at least one of them.
Could there be a crack or somewhere on the intake manifold where extra air is being sucked in?
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1985 Vespa PX150E
1973 Honda CB 350 Four

Learn from other's mistakes ; you won't live long enough to make them all yourself.  Eleanor Roosevelt

Online Tom

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Re: Does anyone know why my bike is doing this?
« Reply #29 on: July 15, 2022, 03:59:38 PM »
+1 Y'ep agree.
From the Deep Deep South out in left field.  There are no stupid questions.  There are however stupid people asking questions.  🤣, this includes me.  😉


Harper's Moto Guzzi : Go Ride , Break Parts, Call me!
Harper's Moto Guzzi. Where we still answer the phone, use the highest quality parts, and also do Transmission, rear drive, and carb rebuilds fast. Call us at 816.697.3411 and get your problems resolved.
http://www.harpermoto.com
Advertise Here
 


Harper's Moto Guzzi : Go Ride , Break Parts, Call me!
Harper's Moto Guzzi. Where we still answer the phone, use the highest quality parts, and also do Transmission, rear drive, and carb rebuilds fast. Call us at 816.697.3411 and get your problems resolved.
http://www.harpermoto.com
Advertise Here