The TPS adjustment thread

[sirthumpalot]

Thanks for posting your experience!  Going by memory, a few guys have told me the went slightly lower on the XC  bikes (that are not street legal in the US), but it's the first I've heard of the EXC being rich.  Is the EXC the street legal model in Europe like it is in the US, or is it the off-road-only model?  Did your bike have the lambda sensor and you removed it, or it didn't come with it?  

[thale]

In Europe the EXC is homologated with a restricted map and a lambda sensor BUT when you bought it the dealer automatically put the derestricted map and remove the lambda, otherwise with the standard map it doesn't run well.

So yes technically the EXC in Europe is street legal. I only run it on the street as a supermoto btw.

I'll continue to monitor my TPS vs idle, I'll maybe even lower the value a tiny bit.

Definitely the TPSTool helps.

Edited January 29, 2019 by thale

[thale]

To summarize, as far as I've understood the TPS thing:

The repair manual is the same for US / AU / EU with the SAME base TPS value (0.400v)

So if you have the crappy US map on the EXC, it's a good thing to raise it to "try" to correct this bad map
But if you have the Euro Map, the base setting should be more or less ok but you can still fine tune it (and it worth it) to get the sharpest throttle response based on your setup (muffler, airbox...).
KTM probably choose to put a slightly high TPS with EURO map to still have a fully functional bike even under very low outside temp (where the mixture should be very lean). It's still better for your engine to run slightly rich than slightly lean and thus prevent flameout or backfire.

Unfortunately for you US guys, the TPS setting is only really effective at idle or low throttle that's why many people over here tune the TPS AND add a tuning box or swap the ECU.

I'm not promoting the TPSTool in any way but I must admit that even for us with euro map it's a cheap way to fine tune the throttle response.

[mxrider124]

I have 2017 350xcf and having the worst flameout on quick snap of throttle and then hard to restart, I am assuming the tps tool would help this situation?

bike runs great off idle 

any ideas 

thanks

[sirthumpalot]

1 hour ago, mxrider124 said:

I have 2017 350xcf and having the worst flameout on quick snap of throttle and then hard to restart, I am assuming the tps tool would help this situation?

bike runs great off idle 

any ideas 

thanks

It certainly could help.  Flameout when you snap the throttle open can be caused by the TPS out of adjustment, and can also be caused by the idle being too low.  If you think the idle is good, then next up would be adjusting the TPS a little up and down to see if you can resolve it.  

[Hammy.]

2 hours ago, mxrider124 said:

I have 2017 350xcf and having the worst flameout on quick snap of throttle and then hard to restart, I am assuming the tps tool would help this situation?

bike runs great off idle 

any ideas 

thanks

we need more info...is the bike stock? 

[BrapSplat]

4 hours ago, mxrider124 said:

I have 2017 350xcf and having the worst flameout on quick snap of throttle and then hard to restart, I am assuming the tps tool would help this situation?

bike runs great off idle 

any ideas 

thanks

Sounds like it needs a remap to me. 

[Horgh]

I thought XCFs didn't have to be tuned badly for EPA reasons, aren't they tuned for off-road use only? 

[sirthumpalot]

Read this review on tt, similar problem, flameout on an xcf,  and fixed with tps adjust:

 

[BrapSplat]

5 hours ago, sirthumpalot said:

Read this review on tt, similar problem, flameout on an xcf,  and fixed with tps adjust:

 

But is it the correct way to fix the issue? The way i see it is enrichening the TPS is attacking the issue from the wrong angle. Most bikes come out of the dealership in a lean state of tune, hence flameouts. There is no loss in correcting this by correcting the state of tune. Once done the TPS should be set, if needed, to the recommended setting. 

Edited February 3, 2019 by BrapSplat

[Horgh]

4 minutes ago, BrapSplat said:

But is it the correct way to fix the issue? The way i see it is enrichening the TPS is attacking the issue from the wrong angle. Most bikes come out of the dealership in a lean state of tune, hence flameouts. There is no loss in correcting this by correcting the state of tune. Once done the TPS should be set, if needed, to the recommended setting. 

I don't know anything about the XCF tune, so someone please jump in if I'm wrong, but in general your statement is correct. Again, I don't want to bad mouth the TPS adjustment as it is an income for at least one valued member here, but in my mind a proper tuning is the answer. Be that via a piggy-back fuel controller, or via an ECU upgrade.

[BrapSplat]

23 minutes ago, Horgh said:

I don't know anything about the XCF tune, so someone please jump in if I'm wrong, but in general your statement is correct. Again, I don't want to bad mouth the TPS adjustment as it is an income for at least one valued member here, but in my mind a proper tuning is the answer. Be that via a piggy-back fuel controller, or via an ECU upgrade.

I had your concerns in mind.

An enriched TPS will be just that throughout the throttle opening all the way to full throttle just to solve a flameout off throttle. This will potentially reduce economy. Quite often the ‘fuel pump’ feature of the likes of the JD tuner and EJK solve this. A slight enrichen down there with the Vortex and remap also, all without adding fuel to the rest of the range.

I have an EJK (Dobek as is the JD), a Vortex and a remap on my bikes. All good.

 

Edited February 3, 2019 by BrapSplat

[Spud786]

Ktm has a history of improperly setting the stock tps setting,  and if someones bike is set on the low side, it wont run as well , as a bike that's on spec. So it doesn't hurt to know where it is. Unfortunately on 2017+ exc bikes, the tps base line procedure is more involved than in years past, where it was extremely simple.

Tps adjustments aide mostly on the bottom.

 

I give an example, 2012 - 2016, the standard tps spec was .60v, but there was a real benefit running more towards .64v.  Some even ran up to .68v, with open pipes.

I did a test not long ago,  utilizing, a .68v tps setting , it was still lean in several areas other than idle, which was overly rich.

So yeah pin point fueling, is a better route, but the tps tool , is a tool that Im glad I have, to ensure where my tps is. when I need to know. Cause as your throttle stop wears or tps sensor itself, settings may change slightly, and need to be able to check it.

 

[Ud_Luz]

1 minute ago, Spud786 said:

 Unfortunately on 2017+ exc bikes, the tps base line procedure is more involved than in years past, where it was extremely simple.

What is the procedure? 

[BrapSplat]

25 minutes ago, Horgh said:

I don't know anything about the XCF tune, so someone please jump in if I'm wrong, but in general your statement is correct. Again, I don't want to bad mouth the TPS adjustment as it is an income for at least one valued member here, but in my mind a proper tuning is the answer. Be that via a piggy-back fuel controller, or via an ECU upgrade.

I had your concerns in mind.

An enriched TPS will be just that throughout the throttle opening all the way to full throttle just to solve a flameout off throttle. This will potentially reduce economy. Quite often the ‘fuel pump’ feature of the likes of the JD tuner and EJK solve this. A slight enrichen down there with the Vortex and remap also, all without adding fuel to the rest of the range.

I have an EJK (Dobek as is the JD), a Vortex and a remap on my bikes. All good.

[BrapSplat]

All owners of EFI bikes who work on them should own the likes of this tool or a multimeter. I have tags soldered in so so its just a matter of lifting the seat and plugging in the probes. The best way with the Bergs. But with the KTM’s easier at the TPS.

[Spud786]

10 minutes ago, Ud_Luz said:

What is the procedure? 

You have to back out the idle screw , all the way, so its not effecting the tps( they are directly connected starting in 2017 exc's, where prior ,the idle screw and tps was totally seperate). The oem setting is .40v on the newer models(course good to make note of where presently is) .   so 2017+ turning the idle screw, increases or decreases the tps setting, that's the difference, from previous. Also its much harder to get to the tps on new bikes, it has a hard cover on it, have to turn the throttle body to get to both screws.

Edited February 3, 2019 by Spud786

[sirthumpalot]

TPS adjustments are fine and work well, it's just one of many ways to make tuning changes.  Why would you not want your sensors at their optimal setting?  Check out the feedback throughout this thread, at www.TPSTool.com and on Amazon to see all the positive feedback.  And as mentioned above, since our bikes come off an assembly line not everything is always perfect from the factory.  As an aside, if adjusting a sensor for the best setting could be wrong, then what about hijacking and altering signals (piggy back tuner)?  That sounds much worse, but in reality works well.  

As far as the full throttle range; the effect is very similar to changing the pilot jet on a carburetor.  The further you open the throttle, the less the effect. For example, if you bump the setting at idle from 0.6 to 0.64, that's a roughly 6% difference.  The same change at full throttle, say from 4.5 to 4.54v, is less than 1% difference.  So you can make a change that is significant near idle speed, but practically insignificant by the time you reach full throttle.  This is also why EPA lean bikes that get a lot of mods, such as a new exhaust, removing reeds, etc.. from an EXC, requires more than a TPS adjustment for the best result.  For bikes that are tuned richer from the factory, even smaller adjustments can make the difference, such as in the review I linked above.  

 

Edited February 3, 2019 by sirthumpalot

[Ud_Luz]

4 minutes ago, Spud786 said:

You have to back out the idle screw , all the way, so its not effecting the tps( they are directly connected starting in 2017 exc's, where prior ,the idle screw and tps was totally seperate). The oem setting is .40v on the newer models(course good to make note of where presently is) .   so 2017+ turning the idle screw, increases or decreases the tps setting, that's the difference, from previous. Also its much harder to get to the tps on new bikes, it has a hard cover on it, have to turn the throttle body to get to both screws.

I wonder if that's due to some Federal, CARB or Euro requirement? 

[BrapSplat]

Who said anything about not adjusting TPS for optimal settings? Im a huge fan of checking the TPS as a process of elimination. Its simple. If the TPS is at its recommended setting while there is still a flameout, then a remap should be looked into. 

The TPS is not there to compensate for poor mapping.

Edited February 3, 2019 by BrapSplat