Print Page | Close Window

My V7 has developed a "stutter"

Printed From: guzziriders.org - moto guzzi forum
Category: Technical
Forum Name: Small Blocks
Forum Description: V35 up to V750 including Breva750, V7, V9 and new V85.
URL: http://www.guzziriders.org/forum_posts.asp?TID=8575
Printed Date: 28 Mar 2024 at 09:07
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com


Topic: My V7 has developed a "stutter"
Posted By: AureusGriffon
Subject: My V7 has developed a "stutter"
Date Posted: 28 Mar 2018 at 08:03
Hello all!

I've just recently joined the Guzzi club, and indeed the motorcycle lifestyle itself. About a month ago now I picked up a 2012 Guzzi V7C in black with around 13,000 miles on the clock. It is, by all accounts, a gorgeous and perfectly capable first street bike. I'm absolutely in love; I don't think I could've made a better decision and I jump at any excuse to ride. Anyway, on to the stuff I'm here for: 

Yesterday, as I was riding onto main campus in the morning, I noticed that the bike was not idling very well. It seemed like it was missing some fires (misfiring, for those of you without an ass-backwards vocabulary). I figured that, since it was a bit chilly out and the ride was very short, the bike hadn't warmed up enough. I rode a bit further after classes to a cafe and the problem persisted. I remedied it by adjusting the "choke" a bit towards the "leaner" direction, which solved the problem temporarily. By the way, I've gathered through looking at other threads that this "choke" is actually just a throttle adjuster and not a real choke, but if I'm wrong someone please correct me, as I only have experience with carburated bikes. 

Today, I went on a longer ride (about 25 miles) and I began to feel a very worrying stutter while the bike is under power, and the idling has gotten worse, to the point that the "choke" doesn't help much at all. It feels as if the bike is bucking each time a cylinder misfires, and its severity ranges from highly noticeable to downright bothersome and distracting. I certainly won't be able to ride with this issue, and that sucks. 

I pulled the sparkplugs and they're quite black, so I've ordered a pair of iridiums. I have a suspicion that they aren't the issue, considering how rapidly the problem worsened and the fact that the old plugs really aren't that bad. I'm definitely not afraid to get more mechanical with my limited toolset here at the dorm (I actually love working on bikes), but I don't really know where to start. I'd really appreciate any insight or experience ya'll might have regarding this issue. I want to get back out there as soon as I can. 

Thanks for the help in advance!



Replies:
Posted By: BobV7
Date Posted: 28 Mar 2018 at 08:17
Sounds electrical to me so probably best to start with that. Sorry, can't be more specific.

-------------
V7 Classic Black and gold was the best. But green & black was nice too. Now blue is in!


Posted By: motomike1400
Date Posted: 28 Mar 2018 at 14:13
I have a V7C, 2010 model. The choke...which really isn't a choke as such, just opens the throttle a little...is only ever needed on a really cold start, ie below 2'C. Maybe a little throttle once the motor catches. Certainly don't ride with the 'choke' on. Don't think that would cause sooty plugs though, as it's just a fast idle lever akin to having the throttle partially open.
Others have had trouble with lambda sensor...could try disconnecting that...search forum for that.


Posted By: Brian UK
Date Posted: 28 Mar 2018 at 15:20
Yes, worth disconnecting the O2 (Lambda) sensor, it's a four way connector. Can't remember if your model has one or two.

-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Vegas Pete
Date Posted: 28 Mar 2018 at 16:51
Hmmmm...... a V7c with idling issues?  Where have I heard this before?

The black plugs are trying to tell you that the mixture is way too rich.  Unless the temperature sensor is telling the engine control module it's -40 degrees outside when it isn't.... or the Lambda sensor is putting out some really bad info.... or both injectors decided to fail at exactly the same time, and in exactly the same way,  the problem is most likely the ECM.  While the symptoms are not an exact match, my 2010 V7c has been doing stuff like this since new, and I haven't been able to excorcise  the gremlin yet.  Tried the Lambda disconnect- about all that did was give me an intermittent check engine light.  For me about all that's left is to change out the ECM, but that sounds a bit pricey and it's still rideable so far.

By the way- does anybody know if the temp sender signal is analog, and if so would shorting the sensor output to ground tell the ECU it's colder outside than it actually is?  If so, this could be the cause of your issue.

Vegas Pete.


-------------
2010 V7 Classic, 2005 Ural Gearup, 1980 Yamaha DT175, 1973 Rokon RT-140, 1969 Rokon MkIII


Posted By: AureusGriffon
Date Posted: 28 Mar 2018 at 18:31
For what it's worth, the temperature guage on the dash is showing correct values. I'm going to try to disconnect the Lambda sensor to see if that is the issue. I do hope the issue isn't with the ECU; I'm going to try out GuzziDiag and see what that tells me before just replacing it entirely if it comes to that.

I appreciate the help!


Posted By: Brian UK
Date Posted: 28 Mar 2018 at 18:43
The temp sender increases in resistance with cold, reduces as it gets hotter. This is the sender in the air intake, and isn't the same as the one displayed on the dash.
 
Guzzi do seem to overcompensate for cold weather in my limited experience. Certainly fuel consumption increases dramatically in very cold weather.
 
What I did on my Norge is put a 20k resistor in parallel with the sender, which has the effect of making the ECU think it's warmer than it really is. Due to the curve of the resistance against temperature, it has no effect when the engine warms up a bit, or in hot weather.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Brian UK
Date Posted: 28 Mar 2018 at 18:44
But most of the low speed issues with all the newer Guzzi models is down to a weak mixture as a result of all the emissions regs. So getting a sooty plug would suggest it's not just the fuel map.

-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: BobV7
Date Posted: 28 Mar 2018 at 19:36
I didn't have the severe symptoms that the OP is suffering but I disliked the way my V7 felt at low speeds and at a constant 70 mph the engine seemed to pulse which wasn't very nice either. After a data check on it that didn't find any problems it seemed like it was all down to emmision regs. I have fitted a FatDuc O2 thingy which is what you can do if you are not Brian but just electronically clueless. This has worked for me as the bike warms up quicker, feels much nicer and is still on the same settings it came with. The engine warning light comes on occasionally but soon goes away and after 5 years I won't be taking it off any time soon. Still sounds to me that the OP's problem is in the electrics and some component has broken down or a connection is shorting.

-------------
V7 Classic Black and gold was the best. But green & black was nice too. Now blue is in!


Posted By: Andyb
Date Posted: 28 Mar 2018 at 20:06
After disconnecting the lambdas, which I would leave disconnected, it may be loose spark plug caps. Look for signs of arcing on the plug tops
Good luck
andyb


Posted By: johnno
Date Posted: 28 Mar 2018 at 20:22
Don't forget the simple first battery connection tight , I doubt it also but that's always my first point of call

-------------
1100 sport corsa , Yam R1, guzzi 650tt rider


Posted By: AureusGriffon
Date Posted: 28 Mar 2018 at 21:14
So I've disconnected the lambda (there's only one sensor on my model) and it seems to have cured the stuttering while under power. I will have to take a longer ride to confirm for sure. It also helped the rough idle a bit but it returned, albeit manageable.

I'm looking to solve this problem entirely so I'm still going to investigate the ECU.

Originally posted by Andyb Andyb wrote:

Look for signs of arcing on the plug tops


What signs should I be looking for? Sorry but I'm a novice.


Posted By: Brian UK
Date Posted: 28 Mar 2018 at 22:41
Run the engine in a dark place. You will see arcing.
 
Have you fitted the new plugs yet? Don't even think about going into the ECU until you have checked all other possibilities.  But make sure there is a good earth to it. Dodgy earth connections can cause all sorts of problems.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Cylvabirch
Date Posted: 29 Mar 2018 at 07:52
I would suggest removing the spark plug caps, clipping the leads back by 3mm and fitting new NGK plug caps. It is also worthwhile checking and adjusting the valve clearances properly when the engine is cold. Use the clearances for Europe .008 inch (0.2 mm) for inlet and exhaust rather than those recommended for USA.


Posted By: Andyb
Date Posted: 29 Mar 2018 at 20:28
Arcing will leave black sooty deposits, there is a known problem of the plug caps coming loose on the plugs. Good advice from the others about cutting back the HT leads etc

If the problem has gone with the lambda disconnected then you can totally remove it and put a staibless steel bung into the socket where it was - available on ebay. I have a slightly later engine with 2 x TBs and it runs much better without the lambdas.
Andyb


Posted By: Cylvabirch
Date Posted: 23 Apr 2018 at 13:24
I had a really bad run out on Saturday with my 2011 V7Classic kangarooing along and being a little devil when slow running. Twice it just died under me in traffic queues. I have disconnected the battery for 15 minutes and reconnected to put the ECU back to square one. I then rode it for about 30 miles and it seemed better than before, but not “cured”. Looking at previous threads on here I decided to disconnect the lambda probe.
The bike instantly felt much better, more revvy and with a nice stable idle. However after 10 miles the engine management light came on and I decided to head home, hoping it would go out again.
It didn’t, and even when I have reconnected the lambda probe it has stayed on. Maddening! I have now disconnected the battery yet again to try to get back to base.
Is there a way of not having the lambda probe connected and not having the warning light?


Posted By: Brian UK
Date Posted: 23 Apr 2018 at 13:41
You don't have a way to read the fault codes on the V7 range do you?

But if the ECU was complaing about the lack of the lambda sensor, I would have expected the light to come on immediately.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Cylvabirch
Date Posted: 23 Apr 2018 at 14:38
Well, after reconnecting the battery the engine light went out and she started fine. Away we went, all feeling fine, but then the light came back on again at 10 miles out and has stayed on all the way home.
Did I do something irrevocable by running it without the lambda probe for no more than 20 miles?
David.



Posted By: V7Chris
Date Posted: 23 Apr 2018 at 14:38
I have experienced various stuttering, misfires, intermittent stalling/failing to isle on my 2015 V7 ii. I have tried getting the dealers to check at service and uploading the latest ecu codes etc. (Waste of time). Fitting the Finebau fuel compensator module (temporary fix but I think it overheated and the problems became worse) I removed this and changed the plugs and plug caps for NGKs because this was suggested as a possible issue. It seemed fine for the first 50 miles then the intermittent mid throttle hesitation/stutter returned. I then disconnected the lambda sensors and have done about 20 miles since. No problems yet and it seems to run cleanly so far. No engine management warning light illuminated yet. I know others that have resorted to this fix have experienced the warning light illuminating, but I think in most cases, it has subsequently extinguished itself. The mkii has a slightly different system from yours  though I think? Single throttle body compared to 2 but I bet the basic system is the same. I remain convinced that the issues with the V7 tough running lies within the ECU system somewhere!
Good luck with getting it sorted and please let us know what the cause/solution is if you find it.
Chris


Posted By: Mike H
Date Posted: 23 Apr 2018 at 16:55
Unplug lambda, goes better and stops being silly, suggests lambda is FUBAR.

2011, now 6 - 7 years old, quite possible.

I imagine ECU is throwing the MIL error because it can't get any sensible input from lambda sensor, 'cause it ain't there - same as, broken connection or lambda not working.

It won't put that light out 'til issue is fixed.

HTH




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Brian UK
Date Posted: 23 Apr 2018 at 17:09
It also detects that the sensor heater is present. But that should have come up immediately.

In our alternative parts section there is a list of sensors which are compatible, no need to pay Guzzi prices.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Mike H
Date Posted: 23 Apr 2018 at 17:14
Originally posted by Brian UK Brian UK wrote:

It also detects that the sensor heater is present.

Does it have one tho? Not all do. Big smile




-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Cylvabirch
Date Posted: 23 Apr 2018 at 17:19
I know less than b@gger all about this sort of thing. It seemed happy when I reconnected the probe and did a ECU reset by disconnecting the battery for 20 minutes. I was pretty upset when the light came back on 10 miles from home.


Posted By: Mike H
Date Posted: 23 Apr 2018 at 17:28
How much is a new lambda probe?

Altho getting the error codes read is the more correct approach to diagnosis


The former is aka "parts darts", i.e. chucking replacement parts at it until it gets fixed. Big smile


 


-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Cylvabirch
Date Posted: 23 Apr 2018 at 17:39
I think the one to replace mine is £95 from Gutsibits.


Posted By: Brian UK
Date Posted: 23 Apr 2018 at 19:59
Originally posted by Mike H Mike H wrote:

Originally posted by Brian UK Brian UK wrote:

It also detects that the sensor heater is present.

Does it have one tho? Not all do. Big smile



Yes, it's a generic 4 wire probe which includes a heater.

Generic (universal) probes can be bought for nearer £30. I did say above don't pay Guzzi prices. The wires are black, grey, and 2 x white.
In fact, on Ebay you can get them for less than £15.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: rapheal
Date Posted: 23 Apr 2018 at 23:25
Have you removed the air filter to check that it is not blocked, or dirty, or even something wedged in the intake passage ?


Posted By: V7Chris
Date Posted: 04 May 2018 at 07:15
Further to the earlier posts and related threads that describe similar issues and symptoms and in particular, disconnecting the Lamda leads and sensors(at least on the mkii).  Summary - to cure poor part throttle running  and periodic stutter/hesitation etc. Having tried the plugs, caps etc. to no avail, I have now completed about 100 miles with the lamdas disconnected. No warning light  illuminated and stutter/misfiring completely gone. I won't be buying new ones anytime soon and my recommendation to anyone experiencing similar issues would now be to try this first as also suggested by others.
Chris


Posted By: Cylvabirch
Date Posted: 08 May 2018 at 18:59
With help from a local Guzzista hero with a laptop, Guzzidiag and the interconnect I am up and running again. The program showed a fault code regarding the lambda sensor. I unplugged it, blew into the socket and reconnected and the fault cleared. We then spent some time on balancing the throttles and getting the right slow running speed and she feels much better.
David.


Posted By: johnno
Date Posted: 08 May 2018 at 20:02
this thread should help quite a few ownersThumbs Up

-------------
1100 sport corsa , Yam R1, guzzi 650tt rider


Posted By: Mike H
Date Posted: 09 May 2018 at 02:40
there you go, all it was was a ‘bad’ connector. 

-------------
"Chicken nuggets don't dance on a Tuesday."


Posted By: Cylvabirch
Date Posted: 12 May 2018 at 10:05
Latest update. She was still not behaving herself when hot and I really struggled to keep her going in slow heavy traffic. She kept surging between about 1400 and 850 rpm unless I held her on the throttle and would conk out at about if she dropped to 800.
I then bought myself the correct interconnect from Lonelec and downloaded GuzziDiag onto an ancient Windows laptop. To begin with I simply could not understand how to do a TPS reset and fiddled around with the trottle stop screw to try to find a stable idle setting, to no avail.
Thanks to Facebook Messenger I was able to contact Mark Bayley in New Zealand who writes new maps for Guzzis. He was appalled that I had EVER have touched the throttle stop screw!!! He guided me through getting the bike back to a stable idle by very carefully adjusting the throttle stop and doing a TPS reset at every step. I am very grateful.
I now await a chance to ride her again and hopefully benefit from Mark’s expertise.
Whilst more comfortable with carburettors, I now feel I have dipped my toe into the 21st century and am fascinated watching all the parameters being displayed on GuzziDiag when the bike is running.
As Mark wrote “Step away from the throttle stop screw”!
David.


Posted By: Brian UK
Date Posted: 12 May 2018 at 13:14
That screw should have been sealed with paint, which might give a clue about not touching it. It's factory set and Guzzi warn that any tampering with it will cancel the warranty on the throttle body.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: Cylvabirch
Date Posted: 12 May 2018 at 16:52
Mine wasn’t.
So perhaps some previous owner had fiddled with it.
Oh well, onward and upward in the learning process.
David.



Posted By: Cylvabirch
Date Posted: 12 May 2018 at 17:24
I seem to recall reading somewhere about a procedure where the ignition is switched on but engine not started, twist grip turned a few times and then everything switched off.
Am I going mad?
If not, what does it do?
David.


Posted By: Brian UK
Date Posted: 12 May 2018 at 17:33
My understanding is that there is a proceedure such as that to restore factory settings for the ECU.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.


Posted By: V7Chris
Date Posted: 12 May 2018 at 17:42
Originally posted by AureusGriffon AureusGriffon wrote:

So I've disconnected the lambda (there's only one sensor on my model) and it seems to have cured the stuttering while under power. I will have to take a longer ride to confirm for sure. It also helped the rough idle a bit but it returned, albeit manageable.

I'm looking to solve this problem entirely so I'm still going to investigate the ECU.

Originally posted by Andyb Andyb wrote:

Look for signs of arcing on the plug tops


What signs should I be looking for? Sorry but I'm a novice.

Has your issue now been resolved? I hope so and I hope you are still enjoying the V7. 


Posted By: Cylvabirch
Date Posted: 12 May 2018 at 18:08
Chris,
A major improvement since Mark Bayley helped me to come back from a very dark place having innocently moved the forbidden throttle set screw.
My slow running speed is a bit high and also my throttle cables were very loose from when I was trying to sort the bike out prior to GuzziDiag and Mark’s help. I rode the bike today and the improvement is enormous but the twist-grip felt very slack indeed. I have taken up some slack in both cables but need to ride it again to see if it is OK.
David.



Posted By: V7Chris
Date Posted: 12 May 2018 at 22:01
That's good. I was just wondering how the newbie - AureusGriffon who started the thread was getting on as they haven't confirmed that their issues have been resolved. 


Posted By: Brian UK
Date Posted: 12 May 2018 at 22:16
The thing to do is remove all the slack in the cables then turn the bars from lock to lock to make sure the tickover speed doesn't vary. If it does slacken off a bit.
The less slack in the cable the less snatchy low speed running will be.


-------------
Brian.

Better 5 minutes late in this world than years early in the next.



Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.03 - http://www.webwizforums.com
Copyright ©2001-2019 Web Wiz Ltd. - https://www.webwiz.net