possible tps issue help

[Dannyrose1]

Hi guys! First post of the year!

So yes i replaced all the pads on my bike today first time ever
Did a fantastic job if i do say so myself thanks to youtube.

So yeah my bike has a problem its running rough
Here are a few things that might identify it
Idles fine
Plugs only changed 3k ago
Holding a steady speed it judders on and off power :/
Excellerates fine with no judders
Holding a steady speed the revs slowly drop off

Ive done a bit of research and it points towards the tps!
Ive found out how to check the values ill see if thats the problem
Tomorrow if it is, can it adjusted? Or just replaced? As they arent cheap

Fz6s2 08 btw, any one who could help would be very appreciated

 

[iSteve]

May need to just sync the fuel injectors.

 

[FinalImpact]

May need to just sync the fuel injectors.

Say what? Perhaps what this is meant to say is; sync the Throttle Bodies?

Injector rates are fixed until "CO" adjust is performed (rare). However, with the use of a 4 port sync tool, you can adjust the idle air mixture so the air fuel ratio at idle attempts to maintain equal vacuum between all cylinders (TB Sync).
Equal Vacuum is based on each cylinder producing the same output power (accelerates the crankshaft an equal amount compared to the others).

I don't see a TB sync helping this unless the fault is a 50 RPM or less.

Danny, how old is the fuel, is there any chance it has moisture in it? When is the last time the air filter was inspected?

Big question: how much RPM drops off on flat land at a fixed throttle position? And when is the last time it performed properly? Miles, months, years???

 

[Motogiro]

What Randy said.^^^^^ I would also suspect fuel quality first. Especially if it hasn't been operated much and it's in the cold.

 

[iSteve]

I don't see a TB sync helping this unless the fault is a 50 RPM or less.

Usually when a engine surges (judders) at a given rpm a TB sync can smooth things out. IMO before buying a new TPS a sync may help and couldn't hurt. If it has never been done then it would be time anyway.

 

[Dannyrose1]

Please remember guys im a complete novice i have no idea what most of you
Are talking about unfortunately. I do understand tho.
I just wouldnt know how to do these things

As for that the bike has done 17,308 miles
Checked the air filter 3 weeks ago when i replaced the clutch cable
As for fuel i fill her up like once a week i ride it everyday its my only
Transport.
Im not sure visually i cant see the revs drop off much but
I can feel it slowing down and then the juddering kicks in
And i have to pull the throttle back more just to maintain that speed.

How can i thottle body sync?
Im going to check tps values right now
And yeah i ride it hard some nights on the way home from work
Up into the 15 thousand revs and up to 133mph lol but shhhh

 

[Dannyrose1]

ITS NOT THE TPS
just checked values were
17 closed throttle
101 open throttle

I think its between 15-18 closed 97-100 open
Should i forgive the 1 on 101?

So what is this throttle body sync and how do i do it?

 

[FinalImpact]

OK - so you have a death wish? You are new to bikes and ripping at 133 mph??

What does "juddering mean". Its not term I can wrap my head around..

Cutting out, misfiring, shaking, hesitating, surging, are more common terms used. So, lets say your going a NORMAL SPEED - 65mph on flat land. WHAT IS IT DOING in say 5th gear vs 6th gear at a steady state?

Are you sure this juddering is not the brakes dragging?

Think twice about those speeds. People become life long Crips for wrecking at MUCH SLOWER SPEEDs! Especially if the bike is not performing properly!

 

[Motogiro]

I've seen a TPS show good on the ohm meter but in fact it was noisy if you looked at it on an O'scope. The vehicle would not run right. Even though the TPS passed the ohms test I decided to put a new TPS in and the motor ran like new. The ECU did not understand the TPS noise and the software put out it's best guess which caused a lot of sputtering.
So yes the TPS test is great to have on the bike but to really tell for sure you should know and use an oscilloscope to test this device for noisy operation.

Kind of like a noisy volume control on an old radio. As you rotate it you hear a lot of static but if you look at it on an ohm meter it shows the proper value and range.

Still your problem may be somewhere else. We've had 2 cases here where the motor seemed to operate fine while the bike was stationary (not rolling) but under way the motor stuttered. The person put the bike on the center stand and found that while in neutral with the motor running the motor ran fine as long as the back wheel was not turning. Turning the back wheel caused the motor to stutter. This was due to cross talk between the speedo sensor signal and the TPS signal. This crosstalk would most likely appear at the ECU plug. Salted roads would most likely cause this condition where the salt contaminates cause conduction of small amounts of current.
If you suspect this is occurring, disconnect the negative battery lead pull the plug from the ECU and clean it. You'll need compressed air, distilled water would be best and dielectric grease. Rinse the connector and blow dry with an air gun. Apply dielectric grease and reassemble.

There are many sensors to make motors run correctly today and though the basic idea of internal combustion are not that complex to our understanding a lot is happening to make the music. This is just on the electrical end.
Good luck and let us know how you're progressing.
Be safe and wear the proper eye protection when working.

 

[TownsendsFJR1300]

You can adjust the TPS but your within the correct #'s. All your adjusting is moving the #'s up or down(ultimatly slightly richening or leaning out the mixture. I'm assuming this is a new issue, no ones played with the CO adjustments thru the dash (and you've had the bike for awhile.)

Besides a high and low #, you ned to check ALL THE #'s in between for any skipping, missing, etc, both up and down using the throttle. Checking it while hot, may, show some skipping.

I tend to agree re a fuel issue. Not mentioned yet, is there any visable rust inside the fuel tank? Has the bike sat, say over winter time, with a partially full tank? I ask in that the fuel fuel filter, if there's rust in the tank, it can clog up the fuel pump filter. Should it partially clogged it'll cause issues.

Being you've had it to a very high RPM without an issue, I tend to doubt that's the issue as it would have reared its head under full load...

I don't know if ethonol is used much over there, however, it can play havoc on a fuel system. If you have access to a fuel system cleaner, ie, Seafoam, Chevron techtron, or even a marine product: "Yamaha "Ringfree" all are very good fuel system cleaners (and top end cleaners). Its cheap enough (not the "Ringfree", but works extremly well) and certainly can't hurt.

If there's any doubt about possible water getting into the fuel, I'd pull the tank and dump it into a CLEAN container. Checking for any contaminents or water may rule in (or out) that potential issue.

Re the throttle syn, there are numerous threads and very good video's here that expalin it very well. If it hasn't been done in its life, it is indeed due..

 

[Dannyrose1]

Sorry no im not new to bikes i mean i new to the mechanical side of things
Learning the ropes so to speak.

Okay so the bikes booked in for a throttle body sync so ill see if that evens
Anything out as everyone said if not its due one anyway.

Thanks for all the feedback guys seems like some pretty complicated
Things going on lol im pretty sure about the rust in the tank thing isnt an issue
It gets filled up all the time and is ridden everyday its never stood still more than a day

Ill have a look at this connection thing because the roads are covered in salt and **** lately

Also look more into the tps

By juddering i mean on and off the power like its rocking me back and forth
Only slightly but enough to feel stuttering spluttering i think is the right word


Ill keep you all posted cheers boffins!!

 

[TownsendsFJR1300]

Sounds like slight "Surging".

Do put some sort of fuel additive (the best possible) in the system (a cleaning agent) and run it a bit with that.

I would do that before the throttle sync...

 

[Dannyrose1]

UPDATE

So the bike is booked in for a throttle body sync
And im going to run some seafoam throught it
But.....

I fixed it anyway lol, i emptied the coolant took the radiator off
Pulled the plugs out and spark plugs checked each was working
And i guess one of the ht leads wasnt fully on! It was on but it must of
Been arcing off somewhere at this steady speed but now
Its back to being my smooth puppy again so happy now i can put
The money towards something nice for the bike

Cheers
For all the effort guys youre all full of ideas and angles to work from
As always been emotional
Signing off Danny boy!

 

[TownsendsFJR1300]

UPDATE

So the bike is booked in for a throttle body sync
And im going to run some seafoam throught it
But.....

I fixed it anyway lol, i emptied the coolant took the radiator off
Pulled the plugs out and spark plugs checked each was working
And i guess one of the ht leads wasnt fully on! It was on but it must of
Been arcing off somewhere at this steady speed but now
Its back to being my smooth puppy again so happy now i can put
The money towards something nice for the bike

Cheers
For all the effort guys youre all full of ideas and angles to work from
As always been emotional
Signing off Danny boy!

Excellent!

BTW, you want to make sure the spark plug cap is secure in the wire. They have been known to loosen up and arc in between the cap and the wire. Should this be the case, simply snip approx 1/4" off the end of the wire and re-screw (clockwise) the cap on.

Also, to make life much easier, put a little bit of di-lectric grease on the rubber part that fits into the valve cover. The rubber won't fight you anymore and will slip on MUCH EASIER. You'll actually hear the snap as it pops onto the spark plug fully.. :thumbup:

 

[Dannyrose1]

Thanks for the tip!! Yeah i think maybe this happened.
You know your stuff, is there a guide anywhere i can use?
I dont want to want to cut anything until im 100% sure i know what
To do lol

 

[TownsendsFJR1300]

Thanks for the tip!! Yeah i think maybe this happened.
You know your stuff, is there a guide anywhere i can use?
I dont want to want to cut anything until im 100% sure i know what
To do lol

There's numerous posts on it, started by "Finalimpact".

If the caps DON'T spin loosly on the wire end, their fine. If it is somewhat loose, its likely you have some arcing going on inside between the wire and the cap. You cn un-screw the cap and inspect. You just don't want to see any black arcing going on inside at that spot.

Simply, if there is some, cut approx 1/4" off the arced (bad) wire end, until its clean,then re-attach the cap. **Cut off the LEAST amount as possible as the wires aren't very long to start with...