Help Me SOLVE this Misfire!

[@jimnotbob]

2 years ago I had the same problem with my 09 Fz6, when cold it would start fine but once it warmed a little one cylinder would drop out intermittently, I also had a strong smell of fuel from the exhaust when it was misfiring. worked my way through new coils, caps, new TPI, checked every vacuum hose, fuel pipe, fuel pressure etc, eventually I opened every single electrical connection on the bike, I found a few corroded connections but the main problem I found was the large ECU block connector had 4 or 5 corroded connectors and the mating pins on the ECU were equally corroded. Once I cleaned those pins up the bike ran sweet. Took me a long time to find the problem, many hours as the bike wasn't flashing any fault codes. I'm a mechanic btw and it almost beat me. Hope this helps.

[@Calvinm]

Thanks for the great insights! Truly helpful idea to check the pins on the wiring harness! Glad you got it sorted 👍

[@jimnotbob]

@@Calvinm did you get yours sorted eventually?

[@lucaherman6227]

Honestly I have no idea. You seem to know a lot more then I. That thing with the hair dryer was genius. Also this video happened to be perfect 5am KZbin content thank you

[@evanburda2156]

my man its 340 am and your right lmao

[@7795Dakota]

I had the same issue and injector cleaner helped clean up the stumble my bike was having a idle. I hope you figure it out.

[@Marktvideos]

Check tps sensor.

[@Calvinm]

I checked it through the diagnostic menu but checking it with a multimeter couldn't hurt. Thanks!

[@PepsiDotMacOnInsta]

Have you got an air leak or crack or a folded over seam in any of the rubberised intake tunnels or a vacuum pipe?....

[@BadWaterMotors]

This was my thought. A leak somewhere. Possibly since the other systems look good.

[@Calvinm]

@DTR 55 I looked closely for that and even sprayed brake clean over the intake runners to find a vac leak but found nothing.

[@djlancer88]

So you can pull the boots right of those wires? How are they connected?

[@Calvinm]

The plastic pencil part of the coil is twisted onto the high voltage wire. Hold the wire and spin the plastic part that connects to the plug and it will unwind from the wire. The rubber boot at the top where it meets the wire can be rolled back as well.

[@thomasrepetti8119]

I have an 05 FZ6 with just over 70k miles, almost all mine. Over the years I have found that the connection between the coil wire and the plug cap to be problematic. Over the years I have had to trim the wires and reconnect the caps multiple time. I see that connection as the weakest part of the otherwise bulletproof FZ6 engine. I never had a miss as bad as yours, but clearly had misfires and rough running issues. Best to gather as much info as possible. Get the IR thermometer and see if you can find the header pipe or pipes that are coolest. If you find 1, swap the 2 spark plug leads from that coil to see if the problem moves. Don't recall if you installed the new coils, but I am guessing you did before planning to check the fuel system. I got so disgusted with the ware to cap connections, I ended up doing a coil-on-plug mod with FZ-07 coils and never looked back.... Good luck.

[@Dannyyzeee]

do you have a link to a write up on the 07 conversion?

[@kurc24k76]

Have you synchronized throttle bodies lately? Also you can try injector cleaning additive for fuel just to see if there is any difference.

[@Calvinm]

I would synchronize the throttle bodies but I don't have the correct tool for the job. Maybe I'll invest in that over the winter. I threw some injector cleaner in the gas after filming this video and it might have helped but it's hard to tell

[@eugeniocarey9249]

If it were as fuel problem it would be there at all RPMs. You need to check the battery voltage when the problem is present at low RPMs when the charging circuit (alternator equivalent) is at low output. It may be the battery voltage under this load is 11 V or even less. With low batt voltage it will not generate the required high voltage at the coil secondary to create the sparks. If this is the problem there could be a current overload even outside the ignition system that's dropping the batt voltage to unacceptable levels and, depending on the overload magnitude, could go away at higher RPMs when the charging circuit has more oomph.

[@Calvinm]

Good point for sure! I'll check the voltage at the low RPM range to see if that's a factor.

[@eugeniocarey9249]

What was the end result on this issue, Calvin?

[@2fast2smooth49]

I had same problem on FZ1 I changed all ignition coils and it work. Maybe the same for yours

[@johnb3041]

Simple I know, but have you already ruled out contaminated fuel? I didn't hear you mention fuel itself in your summary. I had an issue with rain water getting into my tank through a rusted overflow tube inside the tank. The bike still ran, it just had a poor idle until the water burned off after each rain. Is your poor idle correlated with rainy weather? It also meant if I topped the bike up, it'd drip petrol. I would guess the overflow tube is rust prone, as it's steel and rain flows through it from around the fuel cap (mistakenly or not) You/others can test this by siphoning out half a litre or less of fuel from the very bottom of the tank and then letting it sit in a transparent plastic bottle. See if there's any layering in the bottom of the bottle after an hour/overnight. You might also be able to use fuel stabilizer to soak the water up, but I guess that depends on water volume - I've never used it. If anyone does have this problem, the cheapest solution (for me) is a tankbag over the fuelcap to block the rain.

[@Calvinm]

Hmm very good point. The bike has been stored inside for the last year so it hasn't seen a lot of rain but I still will ride it in the rain. I'll check the overflow tube and gas/water content to be sure. Thank you for the ideas!

[@salko_triumph]

I have the same prob ,did u find what it is?

[@MR_JAY_BONES]

Fuel pump filter or fuel pump and clean your injectors like you said

[@RalphGordon74]

I have an almost similar problem. Cold start, bike miss 1 cylinder at low RPM, then slowly loose idling speed until it cut out. I can keep engine going by adding throttle though, it smooth out at higher RPM, but it will continue missing/dying at traffic lights etc, fie entire trip until I reach destination 30 mins later. BUT, if I let it sit a few minutes (ignition off) after the first cut out during initial start, & THEN start few minutes later, it idle steady, no miss, all is well (until tomorrow morning)...

[@Calvinm]

That's a confusing one! It's so hard to diagnose these intermittent problems. I wish I had some ideas to offer you but I don't... good luck!

[@David-mu5rv]

When you did the empty tank test, the risk is over heating the fuel pump. The gas helps keep the pump cool.. It could possibly be the issue. Go to the forums. Very helpful.

[@bratko101]

Did you solve the problem i have the same on yamaha R1 but at 8500 rpm on high gear and rugh idle.. And the sane as you i replace the spark plugs, 1000 km was doing great after that the problem is here, what to do?

[@Calvinm]

I haven't worked on the bike since the video since it's been winter. My plan is to gap down the plugs, check the battery voltage at idle, and go over the wiring harness for any corrosion at the connections. Best of luck!

[@raytokens2291]

When did you last do a valve clearance check. Does the bike get hot quickly? These are mysterious bikes I know cos I have one that ive done 60000 miles on and 99 percent of the work done to it ive done. It may be worth swapping the ignition coils. I will say this though, the charging systems on these bikes aint the best and something as simple as a faulty regulator rectifier can do these things. Also if your stator is burned then it will work but misfires are common too due to not being 3arthed properly. You probably already know this and have done the checks but its worth saying. Good luck bruv

[@Calvinm]

Thanks for the ideas! I'll check the voltage at idle when it's misfiring and see if it's suspiciously low. I checked the valve clearance about 12,000 km's ago and it was all good. Thank you! Ya swapping the coils at this point might just be the move.

[@vsterev]

I have the same bike and the same problem, it hardly impresses me, but I want to fix it. Did you understand what it is from, did you fix it, if you can get more information. I wish you Merry Christmas!

[@Calvinm]

Still working on the problem. My next plans are to gap down the plugs to 0.024" and check the battery voltage at idle while it's misfiring. I'll have an update in the spring when I get this resolved.

[@juandreyer6551]

What was the other problem

[@bratko101]

I just fix my problem by tighting spark plugs when you pass 400 km with new spark plugs just check them if they come loose.. Hope this help you

[@wolfweyr4990]

Did you ever solve this, Calvin?

[@Calvinm]

I did! It ended up being the ignition coils. I made a video on finally solving the problem linked below. kzbin.info/www/bejne/kJanZaVjrZtrn9U

[@wolfweyr4990]

Glad to hear that! This generation R6 also is notorious for coil issues.

[@eugeniocarey9249]

What was the end result on this issue, Calvin?

[@Calvinm]

I still have not yet resolved the issue. When I can, I plan on gapping down the plugs to 0.024" and also checking the battery voltage at idle while it's misfiring to ensure the battery isn't causing the problems.

[@franciscocarrero7031]

Your missfire is the fuel pressure regulator, when it's clogged or not working good the bike on low rpms will fail like a faulty coil but un high rpms works fine.

[@Calvinm]

Hmmm, I'll have a look. Thanks for the idea.

[@cocoloco1994]

Does your bike shows error code 33 or 33? Mine does show at idle but when i rev it its gone but when a closed the throttle at idle its back again

[@Calvinm]

My bike doesn't show any errors. Your code 30 or 33 point towards an issue on the primary side of your ignition coil. Check the wiring to the coils, you might be running on two cylinders currently. best of luck

[@cocoloco1994]

@@Calvinm ive already checked it and turns out, the connector is corroded, somehow the bike bent all of its intake valves, upon checking the timing chain is stretched. W

[@JaviS01]

No problem.... Only because the exterior temperature. Whait until the engie is at the god temperatue

[@SateenDuraLuxe]

I guess you could pour some injector cleaner into the fuel tank and see if that cleans anything up. The Techron stuff seems to work the best in my experience.

[@Calvinm]

Hmm ok. I put some STP branded cleaner in the tank and ran that for about 100km but I didn't see much an improvement. I'll give this techron stuff a try.

[@MrDomo85]

Must say my experience owning and doint 40k miles on my fz6 s2 in all conditions then ...... 1. Don't use heated grips as our poor electrical system from stator to RR cannot cope 2. Coils cause most mossfire issues 3. ECU pins do corrode and short. 4. TPS fault is overated.

[@plpelny]

Clean the injectors. Try additive first. It works for me.

[@Calvinm]

I ran some STP injector cleaner for about 100km after this video and it might have helped but the problem certainly isn't gone. Any brand you recommend?

[@primozkert]

1st. VALVE CLERANCE CHECK AND ADYUST 2nd. SYNCHRONIZING THE THROTTLE BODIES AND IDLE SPEED Service manual : Prior to synchronizing the throttle bodies, the valve clearance and the engine idling speed should be properly adjusted and the ignition timing should be checked.

[@primozkert]

And if you are unsure about insulation of spark plug leads you can spray it with water and see if it sparking... :D

[@johnstull9253]

I have same issue with my bike..... take a temp gun and see which cylinders are running cold compared to the others.... as the bike is warming up, take the temps on header pipes and that might help narrow down which cylinders are miss firing..... I'm getting ready to take the injectors out of mine and clean them, but if your going to do that then I will waist and see what your results are............