V7 I engine cut out at idle

[Roman_cgr]

Hi,

I have an intermittent problem for months on my 2013 V7 Stone that drives me crazy.
Sometimes, when I’m at idle or when I come to a stop with the clutch engaged the engine cut out.
Most of the time it restart by itself immediately (with rpm bouncing briefly at 2K) but sometimes it doesn’t and I have to restart the engine using the starter button.
On rare occasions, when the problem occurred (cut out briefly and restart automatically) the bike seems to switch in limp mode, loss of power and exhaust pops. If I switch off and restart the bike it's back to normal.

I ride 20km to work every days and this problem happen at least once during the ride and mostly when engine is warm.

The bike runs perfectly fine above 2K RPM, no misfires or stuttering.

Since this problem occurred I’ve done the following:
- new NGK plug cap + HT leads + coil terminal
- new plugs
- new voltage regulator (the old one was charging the battery at 16V)
- new cam sensor
- All metal fuel filter
- new air filter
- oil and filter change, valve clearance

I recently invested in Guzzidiag cables to check ECU and I find a couple faults:
- P0201 Injector left : no signal
- P0202 Injector right : no signal
- P0351 Coil left : to low

I cleared the faults multiple time but they come back after a few days…

So my question is, can coil and injectors fail intermittently or is it more like an ECU issue?

[Alfetta]

Personally I would start by checking the wiring to the injectors, coils, ECU, clean contacts, and refresh any grounding terminations. I would also check the switch gear on the bars. I hear that they can be an issue?  A series I V7 is getting a few years on, so corrosion and debris could be an issue.

If cleaning doesn't help, then your off to the modern wonderful world of diagnostic investigations of an intermittent issue in a convoluted structure of cross linked cause and effect devices armed only with an error code and a schematic that doesn't  let you see what is actually happening inside that black box !

Good hunting !

[faffi]

This is the kind of stuff that made me hang onto carbs and points for all these years

The possible bad: 16v can have damaged your CPU. Or a sensor.

The possible good: The fault codes sounds like it doesn't get a signal from the injectors at times, and that one coil is weak. So I would go with Roman_cgr's suggestions and make sure every contact is clean and solid before digging into the costly and more involved stuff.

[John A]

If the engine quits when you pull the clutch lever, it is a sign of crankshaft thrust bearing trouble.

[Roman_cgr]

If the engine quits when you pull the clutch lever, it is a sign of crankshaft thrust bearing trouble.

I don't think I have a crankshaft thrust bearing issue, my clutch works flawless, never had to re-ajuste the slack (3mm), clutch never slipped under load, neutral easy to find. But maybe I'm wrong...

[Roman_cgr]

Personally I would start by checking the wiring to the injectors, coils, ECU, clean contacts, and refresh any grounding terminations. I would also check the switch gear on the bars. I hear that they can be an issue?  A series I V7 is getting a few years on, so corrosion and debris could be an issue.

I have cleaned every contact under the tank (injectors, coils, engine temp sensor, phase sensor...), and the ground termination at the right side of the engine (is there any other ground termination?)
But I never tried to unplug the ECU connector and clean it, thanks for the tips.

I'm wondering if replacing the left coil would be a good move...
A failing coil could throw errors on both injectors at the ECU?

[mr_pacman]

Hi,

I have an intermittent problem for months on my 2013 V7 Stone that drives me crazy.
Sometimes, when I’m at idle or when I come to a stop with the clutch engaged the engine cut out.
Most of the time it restart by itself immediately (with rpm bouncing briefly at 2K) but sometimes it doesn’t and I have to restart the engine using the starter button.
On rare occasions, when the problem occurred (cut out briefly and restart automatically) the bike seems to switch in limp mode, loss of power and exhaust pops. If I switch off and restart the bike it's back to normal.

I ride 20km to work every days and this problem happen at least once during the ride and mostly when engine is warm.

The bike runs perfectly fine above 2K RPM, no misfires or stuttering.

Since this problem occurred I’ve done the following:
- new NGK plug cap + HT leads + coil terminal
- new plugs
- new voltage regulator (the old one was charging the battery at 16V)
- new cam sensor
- All metal fuel filter
- new air filter
- oil and filter change, valve clearance

I recently invested in Guzzidiag cables to check ECU and I find a couple faults:
- P0201 Injector left : no signal
- P0202 Injector right : no signal
- P0351 Coil left : to low

I cleared the faults multiple time but they come back after a few days…

So my question is, can coil and injectors fail intermittently or is it more like an ECU issue?

Where did you get your replacement voltage regulator from and, was it plug and play or did you need to cut and solder wires?  What's the charging output now?

[Off @ 90]

My V7 VII Stornello had this exact problem aka downhill stalling. I found doing a reset  throttle  re learn and Auto learning parameters with Guzzzidiag fixed the problem instantly . Not sure why this problem happens but it always seemed to occur after a long down hill descent off throttle. The procedure for doing the resets is in Beetles tutorial for V7 map install . Hope this helps.

[Roman_cgr]

Where did you get your replacement voltage regulator from and, was it plug and play or did you need to cut and solder wires?  What's the charging output now?

Got it on Aliexpress, it's plug and play:
https://fr.aliexpress.com/item/1005004347394051.html?gatewayAdapt=glo2fra

It output at 14V at idle and at 3K RPM now.

[Roman_cgr]

My V7 VII Stornello had this exact problem aka downhill stalling. I found doing a reset  throttle  re learn and Auto learning parameters with Guzzzidiag fixed the problem instantly . Not sure why this problem happens but it always seemed to occur after a long down hill descent off throttle. The procedure for doing the resets is in Beetles tutorial for V7 map install . Hope this helps.

I have already done several "relearn throttle position" and "reset auto learning parameters" with Guzzidiag, no change...

[Off @ 90]

I have already done several "relearn throttle position" and "reset auto learning parameters" with Guzzidiag, no change...[/

Okay I have had this problem twice both times after long descents off throttle on 4wd tracks . Once ( without Beetle map) stalling problem cured itself after a long fast run aka Italian tune up. Second time with Beetle map installed and  Guzzidiag throttle reset cured it. Have not had problem since then.
It seems like the ecu is not re introducing the fuel at a high enough rpm when off throttle. As soon as the clutch is pulled in the engine cuts (no longer turned by rear wheel engine braking  ) especially when coming to a stop at the bottom of a hill as an example .

[Alfetta]

I recently invested in Guzzidiag cables to check ECU and I find a couple faults:
- P0201 Injector left : no signal
- P0202 Injector right : no signal
- P0351 Coil left : to low

Arm chair analysis...  The ECU did not receive a signal from both injectors. I'm not sure what the signal is, but i'm guessing that the ECU activates the injector coil and once is is de-activated, the collapsed field is detected by the ECU.  IF this is true then if there was no power at the injector coil, the ECU would never see the return.
Also the "coil low" looks to be like a lack of voltage.
therefore you are either loosing electrical power intermittently, or something is pulling the voltage down hard, intermittently.

[Vagrant]

All I know is Sweed Smith went through a few cam position sensors on his. You might search here for his posts on it.

[73 sport]

 For the last many years I have observed too many problems with bikes having computer controlled engine operations and brake control. Is it possible to shit can the computer and go back to simple electrics and carburation. Would any newcomer understand the basics of the internal combustion engine. Is it because the technology is too complicated or engineers really don't understand computer BS? I personally would not buy a bike with anything comp.controlled. There are many bikes available without that crap.

[faffi]

On average, computer controlled vehicles today give far less trouble than fully mechanical vehicles of yesteryear. I used to swear by points ignition and carburetors, then I understood that electronic ignition systems hardly ever fail, and after 40+ years in production, motorcycle fuel injection systems have become utterly reliable and less likely to act up than carburetors, especially in these days of E-fuel. Finally, ABS brakes for bikes are also closing in on 40 years, and they too work mostly without any issues. Cars have used advanced electronics longer than bikes.

So the only merit of the old stuff, which you cannot find on any newer bikes anyway, that I can see is that you can fix them out in the bush with a rock and a piece of string. Dead electronics not so much. In earlier times, when electronics were less reliable, that possibility to fix things like carbs and ignition by the side of the road, at least well enough to get me home, was important to me. Now I do not fear being stranded on any reasonably new and well maintained motorcycle. YMMV

[Roman_cgr]

All I know is Sweed Smith went through a few cam position sensors on his. You might search here for his posts on it.

Thanks, I have read his post on cam sensor, not the same issue. He was getting no spark and no start.

Also the "coil low" looks to be like a lack of voltage.
therefore you are either loosing electrical power intermittently, or something is pulling the voltage down hard, intermittently.

I though about an intermittent drop of power, but don't you think I would get error on other stuff than just left ignition coil and injectors if that was the case?

I think "To Low" in guzzidiag means short to negative or circuit open.

From the V7 service manual:
H.V. Coil P0351 - shorted to positive / open circuit or shorted to negative.
Error cause:
-Shorted to positive: excessive voltage at PIN 1 of the control unit connector.
-Circuit open or shorted to negative: interruption of the circuit or null voltage at PIN 1 of the control unit connector

I will check the wiring between coil and ECU. But what puzzle me is how a wiring problem can cause intermittent problem only at idle...

[tris]

But I never tried to unplug the ECU connector and clean it, thanks for the tips.

Be careful if you do this.
I was chasing a fault on my B1100 and managed to fold a pin over flat when plugging it back together

I had palpitations for an hour while I performed surgery on the ECU to straighten the pin without breaking it!

[John A]

The ignition switch can be a source of intermittent open circuit.