Help! Could it be TPS?

CoryDee

CoryDee

Joined
Apr 19, 2024
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10
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Hello all,
I have a 2013 Sport. I have just upgraded the plugs, the wires, and coil pack. Also adjusted the "idle screw". However when the bike comes up to temp it pulses right around 2000 rpm. Not to mention it feels like its firing on one cylinder before I come to a stop. and is gutless above 4-5000 rpm.

I'm located in Fort McMurray, Alberta, Canada. So would greatly appreciate some recommendations on someone in Western Canada who may be able to help me out.

thanks!
 
When you say you adjusted the idle screw - can you explain a bit more about that?
 
Obvious question, but. was it working like this before you changed things?
 
Gojuu said:
When you say you adjusted the idle screw - can you explain a bit more about that?
Click to expand...
I followed the procedure as laid out in the "Throttle Control" manual. So essentially adjusting the throttle position screw.
 
CoryDee said:
Yes it was. I was hoping these few upgrades would help with all of this.
Click to expand...
Ah ok - glad I asked then.

One thing I learned (that has been a game changer) is to start the bike with NO throttle input and leave it for 15 seconds - don't even look at the throttle. It then runs without issue. I was previously giving it some gas at startup which (I'm lead to believe) was screwing things up in the ECU and making it run poorly.

Got it from the CNW's manual and ever since I've done that, it's been fine
 
IIRC there is a procedure to re set the TPS that goes like this:

IGN off.

IGN on (do not start).

Open throttle to WOT.

Close throttle.

IGN off.

Then you can start the bike, and as Kev says, not touch the throttle until its running.
 
I suggest you check the hose from the idle control valve (IAC) make sure it’s not split, and has clips around it at the valve and the manifold. Then if there is no change remove the hose from the manifold and plug the spigot. See if it runs any better. ( if the engine is cold when you do that, you may have to hold the revs up until it will idle). If it does run better, remove the IAC, clean it and check its operation.

Many folks are now removing the IAC completely, and blocking the cross connection between each throttle barrel. (Not just capping the spigot)

There are a few threads on it, such as this one..

iwilson

Thread 'Idle problem solved'

New thread to make the topic a little easier to find in the future. As some of you know I've been trying to understand and fix the idle problem in this Thread.

Short story, discovered cylinder 2 steals fuel from cylinder 1 at idle via the IAC pipe that links both throttle bodies. This can cause rough running, fouled plugs and much frustration! As I have an aftermarket ECU fitted and the diagnostic tools to monitor the AFR in both cylinders simultaneously I was able to rule out any problem with the programming of the ECU. I wasn't planning on going much further as I could mitigate...
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I’m not sure geographically, but you have the Cootes (father and son in Canada, who know 961’s very well. Send a P.M. to @richard-7
 
CoryDee said:
Not to mention it feels like its firing on one cylinder before I come to a stop. and is gutless above 4-5000 rpm.
Click to expand...
If it's firing on one cylinder it's worth checking whether you have a steel or aluminium fuel rail. The steel one on my 2013 had rusted inside and was blocking an injector. It was swapped out for an aluminium one.
 
comet said:
If it's firing on one cylinder it's worth checking whether you have a steel or aluminium fuel rail. The steel one on my 2013 had rusted inside and was blocking an injector. It was swapped out for an aluminium one.
Click to expand...
Hi , If the fuel rail is tubular (round) it is steel . This bike came with a steel rail as stock so it's probably steel . But he can still remove it and get it cleaned out . While at it , get the injectors serviced and tested . Getting a current aluminum fuel rail will be difficult with the spares situation . Try to reach out to Judd Racing UK and maybe they can sell you a new Norton 961 fuel rail he may get lucky. Or there is Stu at Motorvated UK and Thiel Motorsports DE for parts . Good Luck .
 
Fast Eddie said:
IIRC there is a procedure to re set the TPS that goes like this:

IGN off.

IGN on (do not start).

Open throttle to WOT.

Close throttle.

IGN off.

Then you can start the bike, and as Kev says, not touch the throttle until it’s running.
Click to expand...
Why?

The ECU takes a base value when it’s switched on. Whatever it sees the TPS value as when switched on is effectively 0%.

Part of this is for the ease of TPS replacement. Every TPS will read a minor amount different - and when swapped - and without this a new base value would need to be input.

What you’re suggesting is undone the moment you turn the bike back on.

Whilst not directly relevant to this - that can also be turned off in the Delta.
 
Gojuu said:
Why?

The ECU takes a base value when it’s switched on. Whatever it sees the TPS value as when switched on is effectively 0%.

Part of this is for the ease of TPS replacement. Every TPS will read a minor amount different - and when swapped - and without this a new base value would need to be input.

What you’re suggesting is undone the moment you turn the bike back on.

Whilst not directly relevant to this - that can also be turned off in the Delta.
Click to expand...
Well, I said “If I Recall Correctly”… not that I invented it, or even understood it !

If you wish to discuss or debate the finer points of ‘why?’ You’ll have to contact the Cootes…


IMG_9693.png
 
Last edited:
kev said:
Ah ok - glad I asked then.

One thing I learned (that has been a game changer) is to start the bike with NO throttle input and leave it for 15 seconds - don't even look at the throttle. It then runs without issue. I was previously giving it some gas at startup which (I'm lead to believe) was screwing things up in the ECU and making it run poorly.

Got it from the CNW's manual and ever since I've done that, it's been fine
Click to expand...
I had read that as well when I first got it. Definitely a game changer.
 
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Gojuu said:
prečo?

ECU nadobudne základnú hodnotu, keď je zapnutá. Čokoľvek vidí, hodnota TPS pri zapnutí je v skutočnosti 0 %.

Časť toho slúži na uľahčenie výmeny TPS. Každý TPS bude čítať menšie množstvo inak - a keď sa vymení - a bez toho by bolo potrebné zadať novú základnú hodnotu.

To, čo navrhujete, sa zruší v momente, keď znova zapnete bicykel.

Aj keď sa to priamo netýka, dá sa to vypnúť aj v Delte.
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mam otazku. Ak sa voľnobežné otáčky nastavia ručne skrutkou na doraze plynu, tak sa škrtiace klapky skutočne otvoria na cca 2-3%. Vyhodnocuje ECU pri zapnutí zapaľovania túto polohu ako 0%? Neprekáža táto nesprávna informácia pri tvorbe palivovej zmesi? Je palivová zmes bohatšia ako by mala byť?
 
Marián P said:
I have a question. If the idle speed is set manually with the screw at the gas stop, the throttles will actually open to about 2-3%. Does the ECU evaluate this position as 0% when the ignition is switched on? Doesn't this incorrect information interfere with the formation of the fuel mixture? Is the fuel mixture richer than it should be?
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You need to do a TPS calibration . It is in the notes of SXTune. Once your idle is set , then you establish 0% and 100% throttle voltages. You should also turn off the throttle auto zero function. This works very well for me.
 
TonyA said:
Musíte vykonať kalibráciu TPS. Je to v poznámkach SXTune. Po nastavení voľnobehu nastavíte napätie škrtiacej klapky 0 % a 100 %. Mali by ste tiež vypnúť funkciu automatického nulovania plynu. Toto mi funguje veľmi dobre.
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Norton ma v starobe prinútil učiť sa veci na PC :-DI sa podarilo nastaviť plyny 0-100% a vypnúť auto TPS. Perfektný deň - tento bicykel ma veľmi baví :-P
 
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