Need Help Intermittent Stalling at Idle, Code 12

ArielAzure

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Hello all, I recently bought myself a 2009 Yamaha FZ-6 Fazer with 45k miles on the clock. It also has the dual headlight mod and a delkevic slip-on exhaust. The bike rides fantastic and sounds amazing, with plenty of power throughout the rev range.

Unfortunately, it has an issue in which the bike will randomly stall out in neutral. Once this happens the motorcycle will turn over, but not start, eventually displaying a code 12 error. However, after 3-6 attempts of cranking the engine over to start it, it eventually springs back to life with no issues, no active codes and a healthy idle. The issue only ever happens when idling and has never happened whilst in gear nor whilst moving. Idles around 1350rpm when warm.

So far I've tested the resistance of the CPS and TPS, both of which are in spec. I've replaced the bulbs for LEDs to reduce the load of having dual headlights on the battery, and also bought and installed a fresh battery. and the battery reads 13.1v when the bike is off and 14v at idle (likely due to less power draw coming from the more efficient LEDs). No blown fuses, and relays appear to work fine when tested in diagnostic menu. Fuel pump primes well and consistently. Kill switch has been taken apart, contacts cleaned, and reassembled.

I understand it's quite the strange issue, and I'm debating on whether I should have a motorcycle mechanic come and take a look at it. These forums have been helpful and informative however. I know it may be a difficult issue to diagnose, but any help would be appreciated. I love this bike and would like it to be with me for years to come, but the risk of it leaving me stranded from home has meant I haven't ridden it very much as of recent.
 

TownsendsFJR1300

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You may try removing the air filter and when the issue arises, spray some starting fluid into the
TB's and see if it starts...

If no difference, again when acting up, check for spark. An in-line tester
would make it easier or a spare plug just plugged into #4 cap and grounded so
it's visible


.

.
 

Gary in NJ

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Welcome ArielAzure. Let's get this problem sorted so you can enjoy your bike without worry.

My go-to resolution for intermittent electrical problems is to check every connector for corrosion, especially the connections at the ECU and the various sensors. Carefully disconnect the harness from the device and spray both sides with contact cleaner. If there is room, use a toothbrush or similar brush to abrade the metal contacts. If you can't get to the contacts with a brush, simply connect/disconnect a few times when the connectors are wet, respray to flush, and allow to dry. Before making the final connection be sure to use a little dielectric grease on the perimeter of the male connector to keep moisture out in the future - don't skip this step if the bike is stored outside.

This should solve the issue - but even if it doesn't you can now eliminate this as a potential issue. The other benefit is that you now have ensured that each connection is properly seated.

Side note/story time:
All of my bikes are stored indoors in a garage and my cafe racer is never ridden in the rain. Last August I washed the bike and took it out for a nice long ride with a friend. After a few hours we stopped for coffee and when I got back to the bike the battery appeared dead - like zero volts dead. I had my friend give me a push and the bike started right up with a classic push/jump start. I got home and again the bike wouldn't start. I assumed it was the starter solenoid acting up and parked the bike until I had an opening on my stand to address the issue.

Two weeks ago I got the bike on the stand. With a fully charged battery and the ignition key in the on position nothing worked...except the tail light. My first thought was corrosion in the ignition switch. I removed, disassembled and cleaned the switch contacts. Sure enough there was corrosion (the bike lived 100 yards from the ocean before I bought it) on the contacts, but upon reassembly the bike displayed the same issue.

I began the process of checking connections and noticed the headlight flickering when parts of the harness were moved. I could get the headlight to remain on, but as soon as I engaged the starter the electronics would once again die and I'd have to start moving the wires to the "sweet spot" to make a connection. I narrowed down the offending wire to the main ground that runs from the battery to the frame. I checked the battery side and all was good. I then checked the frame side and the cable looked good. Touching the wire to the engine it immediately made contact. To confirm this I removed an engine cover bolt and secured the wire lug directly to the engine case - and the bike started right up. I checked continuity of the wire while moving it around to see if there was a break in the wire below the insulation. Seemed good. I decided to just put it all together and that's when I saw the actual problem - the bolt that secured the cable to the frame had a bit of corrosion on the threads that made contact with the wire lug. When I moved the harness around it allowed some movement at the lug that made a slight contact - enough to make the light...er...light, but not enough contact to allow for starting current.

I cleaned the bolt and frame with contact cleaner and a wire brush and put it all together - problem solved. The moral of the long story is: the slightest bit of corrosion in the right (or wrong) place will shut down your bike. Had I not washed the bike the day of this ride, this problem may have never shown...until it was washed at a later date. That little bit of water was just what it needed to create the perfect conditions to become a problem. The problem itself was inevitable.

Second side note: My Ducati is now on the stand to swap out the TPS (calibration of the TPS is a total PIA) and then the $500 FZ6 goes on the stand. That bike will get a dedicated rebuild thread.
 
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ArielAzure

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UPDATE
Hello all, thank you for the helpful replies! Whilst I was gone I went and experimented with a few things.

Firstly I noticed the rubber seal around the air filter had developed a slight tear. I'm unsure if this would have had any effect but I decided to replace the air filter and it's seal regardless.

Next, I went under the tank and inspected and cleaned the connectors, with more attention on the CPS, and then rechecked the ohms reading. . No signs of corrosion and a healthy reading on the CPS. Admittedly, I did not check the ECU's connectors as I forgot. I then left the bike to sit for a few days (hence the lack of any updates until this point).

Checking the battery, it still reads as 13.1v so that reduces the culprit being down to parasitic draw. The last time the bike was turned on, it successfully started up quickly and idled smoothly but stalled and would not turn on. However, no code 12 was displayed. A few minutes later the bike started up with no issues. Despite this, and the general trend of the bike only refusing to start after stalling, it would not start today. I should also mention that the fuel pump noise is definitely more pronounced then before, but that may be down to the new air filter.

Finally, thank you for the wonderful suggestions on what to do next. I will firstly recheck all the fuses for any breaks, wires for cuts and connectors for corrosion (including the ECU this time). If this doesn't work I'll try adding starter fluid to the ITBs, followed by the spark plugs if the aforementioned do not resolve the issue. The weather has not been great due to storms coming in from overseas, but I'll do my best to keep you fellow FZ6 owners up to date on my progress.

I'll attach a video below of me attempting to start the engine, and yes, rest assured that I intend to correct the cosmetic imperfections once the bike is relatively working. The difference in pitch during cranking over is due to me slightly opening the throttle at times, just in case the engine is flooded. Again, thanks for the support and I hope we a community we can find a solution to this!
 
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Cocoloco

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I've experienced this on a different bike, it turns out the CKPS when hot is faulty , cooled it down and starts right up and stall when again when hot.
hope this helps.
 

Cocoloco

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Welcome ArielAzure. Let's get this problem sorted so you can enjoy your bike without worry.

My go-to resolution for intermittent electrical problems is to check every connector for corrosion, especially the connections at the ECU and the various sensors. Carefully disconnect the harness from the device and spray both sides with contact cleaner. If there is room, use a toothbrush or similar brush to abrade the metal contacts. If you can't get to the contacts with a brush, simply connect/disconnect a few times when the connectors are wet, respray to flush, and allow to dry. Before making the final connection be sure to use a little dielectric grease on the perimeter of the male connector to keep moisture out in the future - don't skip this step if the bike is stored outside.

This should solve the issue - but even if it doesn't you can now eliminate this as a potential issue. The other benefit is that you now have ensured that each connection is properly seated.

Side note/story time:
All of my bikes are stored indoors in a garage and my cafe racer is never ridden in the rain. Last August I washed the bike and took it out for a nice long ride with a friend. After a few hours we stopped for coffee and when I got back to the bike the battery appeared dead - like zero volts dead. I had my friend give me a push and the bike started right up with a classic push/jump start. I got home and again the bike wouldn't start. I assumed it was the starter solenoid acting up and parked the bike until I had an opening on my stand to address the issue.

Two weeks ago I got the bike on the stand. With a fully charged battery and the ignition key in the on position nothing worked...except the tail light. My first thought was corrosion in the ignition switch. I removed, disassembled and cleaned the switch contacts. Sure enough there was corrosion (the bike lived 100 yards from the ocean before I bought it) on the contacts, but upon reassembly the bike displayed the same issue.

I began the process of checking connections and noticed the headlight flickering when parts of the harness were moved. I could get the headlight to remain on, but as soon as I engaged the starter the electronics would once again die and I'd have to start moving the wires to the "sweet spot" to make a connection. I narrowed down the offending wire to the main ground that runs from the battery to the frame. I checked the battery side and all was good. I then checked the frame side and the cable looked good. Touching the wire to the engine it immediately made contact. To confirm this I removed an engine cover bolt and secured the wire lug directly to the engine case - and the bike started right up. I checked continuity of the wire while moving it around to see if there was a break in the wire below the insulation. Seemed good. I decided to just put it all together and that's when I saw the actual problem - the bolt that secured the cable to the frame had a bit of corrosion on the threads that made contact with the wire lug. When I moved the harness around it allowed some movement at the lug that made a slight contact - enough to make the light...er...light, but not enough contact to allow for starting current.

I cleaned the bolt and frame with contact cleaner and a wire brush and put it all together - problem solved. The moral of the long story is: the slightest bit of corrosion in the right (or wrong) place will shut down your bike. Had I not washed the bike the day of this ride, this problem may have never shown...until it was washed at a later date. That little bit of water was just what it needed to create the perfect conditions to become a problem. The problem itself was inevitable.

Second side note: My Ducati is now on the stand to swap out the TPS (calibration of the TPS is a total PIA) and then the $500 FZ6 goes on the stand. That bike will get a dedicated rebuild thread.
That ducati adjustable TPS really is a PIA to calibrate!
 

RayO

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I have had a start and run for a while but stop and restart again and repeat. Turned out to be a fuel pressure problem due to a fault in the pump. The pump ran electrically ok but was not quite right in its assembly. You can easily check pump pressure with pressure gauge. Make sure pressure is at spec when the pump is running. If it is not or fluctuates maybe that's the issue.
 

ArielAzure

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UPDATE 2
Hey guys, I am sorry about the lack of communication in my end. For a while, there hadn't been anything of note to report. For a while I was completely stumped. I'd work whenever the weather would permit which unfortunately was not often, however I have made a few crucial findings.

For starters i inspected the ECU's wiring, and upon inspection I realised the grey part of the ECU connector was bent upwards, potentially squishing the top line of wires. Following this, I decided to removed the ECU. There was no sign of leakage, damage or corrosion on any of the pins, and all had a golden colouration. After repairing the ECU harness and reinstalling the ECU, the bike fired right up without any issues, and ran smoothly thereafter, no more code 12. Unfortunately, this did not last for longer than one day.

The next day I went again to start it, to no avail. It cranked over and over and over, but never started, and the code 12 had returned. The CPS still read within spec and even after unplugging and replugging the ECU it still would not start. The battery was fully charged at 13.1v. At this point I was suspecting it was either the ECU or the wiring harness.

Out of pure desperation I unplugged every connector, cleaned them with isopropyl alcohol, brushes, cotton buds and toothbrushes, before allowing them to dry. I again checked the CPS, but also checked the ECU harness and CPS harness for continunity, which it had. I also allowed the bike's battery to remain unused and undisturbed on the trickle charger. Also checked the stator's resistance which was in spec.

That leads us to today, in which I was testing for the presence of spark, so I removed a spark plug for testing. I could smell fuel but could not see spark. However, I soon realised that my spark plug was not fully sat down on the ignition coil. Upon doing so, within a few cranks I saw spark and the bike fired right up! After reinstalling the spark plug the bike idled wonderfully, but a new issue had developed. The bike would suddenly die after a minute or two, but would start up again if you attempted to restart it. Now suspecting a fuel problem, I cleaned the connectors for the fuel pump, air intake pressure, air temperature sensors and ignition coils.

Surprisingly it seemingly has worked, with the bike idling with no issues at all. Today alone, I have started the bike up 5 times with no failed attempts! Not quite sure what fixed the issue but I suspect it was a combination of multiple issues from loose, corroded or wet connections at the fuel pump, starter solenoid and/or the ECU. It's too soon to say if the issue is fixed for good, and the week ahead is forecasted to be constant rain. I'll come back with an update the next time I am able to start it on a dry day!

I'm really grateful for all of the contributions and support I have gotten regarding this rather odd issue, it's been such a wonderful experience to troubleshoot and find advice on these forums. Big shout-out to Gary for seemingly being spot on with the solution! Wish I had done that from the very start and saved myself the headache! I hope this experience can help someone else out if they're in a similar situation. Now then, time for a well deserved rest!
 

toybox

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Maybe you can check if there are any leaks in the combustion chamber. I had a leak in the fuel pump so there wasn't enough gasoline pressure to fire the gasoline.
 
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