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Discussion Starter #21
The higher octane fuel is a cleaner fuel and burns better, I can't see that being the culprit but the TPS recall was done on it already last year and the diagnostics all check out. If it's a plug wire damn I gotta replace the coil too.
 

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My diagnostic readings were well within spec and it turned out being that my TPS was bad. After it was replaced the readings were the exact same on the new one but it fixed all my problems. You might have something else going on there but I wouldn't rule out the TPS because of the diagnostic test. You should have it swapped out anyway for the peace of mind, it won't cost you anything.
 

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Guys, enough w/ the fuel and octane....that ain't it.

You've got a spark issue.
Mine was bad for a while and I actually measured the exhaust pipes and found one to be about 200°F cooler than the others. Try swapping the #1 and #4 plugs & plug caps or the 2&3 (they are on the same coil).

My real BAD miss is gone but there still remains a slight miss when I slowly rev the bike at a stand still. It also surges a bit at parking lot speeds.

My next step is to take the new plug cap assy and a new plug and swap each and every cyl to see if the miss goes away. If that does not work...I'm on to new wires.

Here is one more thing I found out about the NGK plugs (thanks to 03zq8):
The thin wall on the ceramic is prone to electrical puncture

 

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An intake leak could easily cause both a crappy idle and a problem under heavy load.

If you determine its getting proper spark, have someone smoke test the intake. I would also check fuel pressure.

Definitely run a bunch of Seafoam (or any other good injector cleaner) through it before you explore expensive options.
 

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^ +1 it sure can. I was going nuts trying to track my low RPM misfire problem (sounds exactly the same as yours), the engine even threw an error code for the intake air pressure sensor. Turned out to be a red herring. I was paying so much attention to all the sensors and the fact that it's fuel injected and computer controlled that I didn't even think of mechanical situations that could cause the some problem. Turned out my airbox had separated from the throttle body stacks on the right side and was just resting on top. If it was carbed I immediately would have suspected an air leak of some kind. I figured it out because I leaned on the airbox while the bike was running and the revs went way up. These things do sound pretty cool as a 3 cylinder through the scorpions though. It was pretty badass.

nitrous is right about the TPS, they typically fail without showing any problems in the diagnostic. I seem to be in the vast minority because after a while mine actually turned the check engine light on, but most don't seem to.

If you have an induction timing light it's pretty easy to spot misfires by hooking it up to all the plugs.
 

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butt marker
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I was thinking about this because I have the same problem.
How many people have checked the voltage output on their batteries?
I know my battery is due for replacement soon and I think that's what is causing the random idle problems.
 

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UCLA
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didn't touch anything on the bike yet except for filling the tank with the lowest grade possible.. 87.. funny thing is, it actually seems a bit better.. i think i get better throttle response.. perhaps it's only my wishful thinking that led me to believe it's better now..

will check the airbox and spark plugs soon though.. (it better not be the tps cuz i had that replaced under recall a month ago)
 

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Now that you're running with a proper burning gas for the engine, ***lower octane burns faster than higher octane, by the way*** unplug the battery for about 15 mins. (both positive and negative) then reconnect it to reset the ECU to default.
 

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Do you have any facts supporting this claim? I ask because AFAIK there is nothing the ECU can do to "learn". It's correct that modern cars are capable of "learing" by way of O2 and knock sensors and "adapting" based on driver inputs, among other things, and that by removing power to the computer those settings are reset back to zero. What can the FZ6's ECU do? It runs on a map that never changes.
 

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Yup, but it can detect sensor that might have fed some values other than what is currently being sent. The ecu actually reacts to inputs. If any faults or variations to inputs from sensors are kept, then there can be a change to how the bike runs.
 

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It does react to inputs, but in realtime only. For instance, run the bike and unplug a sensor. It will immediately resort to the failsafe mode for the particular sensor, throw on the check engine light, and put a fault code in the diag screen. If you plug the sensor back in, it goes back to normal running mode and uses inputs from the sensor. It's not learning anything, and if the sensor is giving bad inputs the ECU will either accept them and use it to calculate fuel, or if it's out of spec disable the inputs from the sensor and use the failsafe mode. The ECU can only decide to accept a sensor or reject it in real time, it can't figure anything else out or make decisions based on past inputs.

Think about the slew of TPS problems and how everyone's ECU responded to those.
 

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Whenever there's a problem with the bike, I always start with the basics. Any computer, program or application can pick up a bug or two when subjected to conditions outside of its intended parameters. Unplugging and re=plugging is simple enough to do to start your diagnostics.
 

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Hi guys,
thank you for those replies - this is vary useful - I already made a list of things I have to check out.
I have same problem with low rpms on idle and when the engine warms up, but not every time. Reading a lot of replies for the fuel, make sense as I'm riding with 100 octane euro standard and this morning the problem appears when I've got full tank of same 100 octane. However I'm usually using this king of fuel and again the problem with 800-850 rpms at some moments and not pleasant engine sound appearing randomly. My battery was replaced few months ago. At these low rpm's the display becomes less brighter, but this is normal I think.
I never checked the plugs or did any diagnostics. I replaced the air filter and in my opinion this was probably the start of the problem..but I'm not sure.

I'll start with some basic checks, before any diagnostics or plug/ wires / sparks replacement.

If any body have solid solution - I'll be again very thankful.

Thank you for these good advices and keeping this great forum.
 

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I don't go for that no high octane stuff. I run 93 octane pure 99% of the time and have zero problems. 'course RPM's don't scare me at all. I have zero problem riding around at 8K in second gear. I try to blow through the redline at least once every time I ride. Fazers were not built to be babied. Keep her clean, ride her hard and let her cool down before you put her away. Sorta like a girl scout.
Seriously, find an open section of highway and run her through the gears at redline. Several times. She will like it. Air filter might be a good thing to look at. I have 2 K & N's that I change out once a month. That is excessive but I stay ahead of the curve that way.
How are your valves? I have about 24K miles on my '05. The PO said he had them checked at 18,000. I had them done at 22,000. They were all within spec but I had the mechanic put new shims in 2 exaust valves to get them closer to all the same. I cost under 300 dollars to have the vales looked at and the collant changed so I plan to do that again this winter. Not because they need it but because the closer to the equal they are, the better the bike runs.
Fuel. air, spark. It is always one of those 3. With most machinery a few cents of prevention will save you lots of dollars in repairs.
 
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