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sirthumpalot

The TPS adjustment thread

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1 minute ago, Ud_Luz said:

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

The separate idle circuit is just a different throttle body design.  Some bikes have been that way from the start, but it was only recently that the EXC got that style throttle body.  

If you scroll back to my post on January 17 in this thread, I posted a video showing how to make the adjustment on the newer bikes.  I'm obviously not a movie star, but I think the information is there. ;) I'll make a video soon showing the throttle body, idle setting, etc..  in more detail. 

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1 minute ago, Ud_Luz said:

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

They changed to an SXF type thottle body , not sure the reason.

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2 minutes ago, BrapSplat said:

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. 

You certainly could get in there with a tuner and effect the same change, but for many cases (EPA locked ECU like the EXC, rest of the map is fine such as the XC, etc..) a TPS adjustment can solve the problem with no unwanted side effects and with less hassle and expense.  

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You guys in Australia get the Best maps, ktm puts out , the U.S. maps generally suck.

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22 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.

Huh, I didn't know that. Thanks for the info, that's very helpful.

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7 minutes ago, sirthumpalot said:

You certainly could get in there with a tuner and effect the same change, but for many cases (EPA locked ECU like the EXC, rest of the map is fine such as the XC, etc..) a TPS adjustment can solve the problem with no unwanted side effects and with less hassle and expense.  

While I understand your thinking, the TPS shouldnt be relied upon for fueling issues beyond what it was designed for. Ok, a quick enrichment of the TPS may solve the flameout issue but its not the correct method. For some that suits.

I have three EFI bikes. Ive had TPS adjustment issues. Ive soldered in leads so its a quick method of checking the position with a multimeter. A dyno run has been performed on each bike. Each bike needed fueling adjustments. 

 

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4 minutes ago, Spud786 said:

You guys in Australia get the Best maps, ktm puts out , the U.S. maps generally suck.

Dunno Spud. Rex Fleiter is doing a killing with the remaps. I like to open my bikes up so a boost in fuel is mandatory.

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I feel like we should all be sitting around a tool bench with wings and beer while having this discussion.  :D

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37 minutes ago, sirthumpalot said:

The separate idle circuit is just a different throttle body design.  Some bikes have been that way from the start, but it was only recently that the EXC got that style throttle body.  

If you scroll back to my post on January 17 in this thread, I posted a video showing how to make the adjustment on the newer bikes.  I'm obviously not a movie star, but I think the information is there. ;) I'll make a video soon showing the throttle body, idle setting, etc..  in more detail. 

Kind of glad I have a '14 500exc with 50 miles as a spare for when my '12 500exc croaks. :) 

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Hi Thumpers and particularly sir thumpsalot,

I have a 2014 KTM 500 EXC. 

I had Thumper Racing install their 610  Big Bore kit on it and Travis had his buddy at the KTM dealership remap the ECU. I installed a Dobeck gen 4 AFR controller and lashed the beast to a long track snowbike conversation kit and I was in heaven, it ran like a champion.

Skip to this year,

 I had Thumper Racing stoke the motor to a 660 cc, purchased a 2018 throttle body that Thumper racing bored out to 46 mm, changed the fuel injector connector clip and the TPS connector clip, and added a Vortex ECU programmed and sold by PR2 racing specifically mapped for the big bore 610 / 660. I also installed an Inovation AFR gauge where the Dobeck controller gauge used to be to monitor AFR’s. Jeff at PR2 said a closed loop system like the Dobeck gen 4 would conflict with the PR2 ECU so I removed it.

The problem is this once friendly beast back fires like Jaba the Hut after a garbage can full of nachos after supper bowl. During and after warm up once I back off the throttle the backfire is crazy bad. Do you guys think it’s: a TPS issue , or an ECU issue, or the fact that I’m running a 2018 bored out throttle body on a 2014 keyed bike? Any insight would be greatly appreciated.

Thank you Thumpers

Dr. Dirt

B) 

 

 

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Hi Thumpers,

what if I accidentally wired the TPS wrong , would it run but backfire if red and blue were reversed?

what if I accidentally wired the 2 wire fuel injector clip, would it even run?

 I tried to zero out the TPS per the Vortex instructions but that’s for NON Keyed bikes. How do you zero out TPS for keyed 500 EXC with integrated RUN / STOP / START switch and keyed ignition, different than 2018 XCF that came with new style throttle body and only an electric starter switch and a kill switch?

remember I’m running the 2018 throttle body with a yellow knob on the bottom and a red idle knob on top.

thanks in advance for any help you can provide 

Dr. Dirt

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You've got a lot going on there, lets take it a piece at a time.  

If the wrong wires went to the injector, it would not run.  If the wrong wires went to the TPS, it might start but certainly run very badly, and I would expect the ECU to complain (error code).  If the correct group of wires went to the TPS, but in the wrong order, I would expect similar; it might start but would certainly run very badly and the ECU would likely complain.  

If you're wiring stuff by hand, as opposed to having a pre-wired harness that just clips in and is known to be correct; then what you should do is get the schematic for the ECU and for each sensor and injector on the throttle body, and draw out on paper which wire goes where.  Then double check that your bike wiring matches what you have on paper.  Trust me that life is easier if you draw it on paper.  

Then I would break out the docs for your ECU and look at what it's expecting for the TPS.  The Vortex will have a way to learn the initial and full throttle TPS values.  So what you would do is adjust your TPS to be in the range that the Vortex is expecting, then follow the Vortex procedure for learning the initial and full throttle values.  Maybe give Vortex a call to see if the procedure is different for a keyed bike.  My guess is it's similar to a non-keyed bike, except that you'll need to turn it on and off manually, as opposed to the non-keyed bike which automatically powers off after a few seconds.  Once that is done you should be all set to start playing with the maps.  Maybe go back to PR2 racing with questions about the fuel and timing maps.  

The Pro TPS tool is the most convenient to use.  Watch the first HowTo video on this page to see how to set the TPS using the pigtail and the Pro tool, on both keyed and non-keyed bikes, and new or older style TPS.  That should get you going with the TPS part of your project:  https://www.tpstool.com/tps_tool_howto_videos.htm

Let us know how you do! 

Edited by sirthumpalot

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Thanks sirthumpalot,,

I watched your video several times until the wee hours, that’s where I noticed the difference in the TPS wire coloring and configuration from old wiring harness to new wiring harness. I took your advice and requested a schematic from PR2, I suspect I have the 5.0 volt TPS wire and the .64 volt TPS wire reversed and will try that first. When I first completed the build I had the wiring wrong on the TPS and it wouldn’t even fire. I inspected the clip wiring colors on a friends 2018 450 and made a change, plugged it in and it fired but I was plagued with the backfire issues. Like you said with wires reversed it might run but run badly. I too would expect ECU to have complained but no. One thing I know for sure is the black wire is correct, that leaves the blue and the red to switch.

Question: is there polarity to the Fuel injector 2 wire?

 I ask because I originally had the FI wires pinned into the new clip to match the position I saw on the 2018 model and it wouldn’t spray, so I reversed them and low and behold, I got spray. The FI body is plastic so no ground, wouldn’t it spray either way you wire it since it’s a 2 wire clip. I’m wondering if the TPS and the FI might share a ground or something and affect each other if miswired?

 Either way I intend on purchasing one of your TPSTools once I get the wiring figured out.

 Thanks 

Dr Dirt

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You are correct, the wire order (position) is different between the TPS's used on different throttle bodies.  Look at the wire colors on the Pro model TPS Tool adapters in this picture (bottom is Model-1, middle is Model-3), these are the female plugs.  For our single cylinder EXC, XCF, XCW bikes, black is ground, green is 5V, red is feedback.  The colors on the adapters might not match colors on the bike itself, so go by order of the wires when comparing to the bike.  Maybe that will help you figure out your wiring.  Also different bikes will have a different order (such as the adventure bikes), so the wire position might be different if your throttle body came off of a motor other than an EXC, XCF, XCW.  

For the fuel injector, I believe polarity is important and they have to be wired the right way.  Even though there are only 2 pins (+ and -), they have to be wired correctly or it won't work.   Very few things don't care about polarity, such as incandescent light bulbs.  But most other things do care. :)  

With a complicated system, if one thing is wired incorrectly it can very easily affect other things in the system.  It all depends on the design of the system. 

Edited by sirthumpalot

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Hi Sirthumpalot,

 I double checked all the TPS wiring and everything checked out.

 I ordered one of your TPS meters but it won’t get here till next week.

 I experimented and loosened the TPS  torques screws and rotated it counter clockwise and the bike settled right down and no more popping and backfire on deceleration. My question is since this 2018 throttle body has been bored out to 46 mm, should I still shoot for .54 volts or another voltage?

thanks for your help

Dr. Dirt

 

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You've got so much custom stuff there (bored out throttle body, vastly larger cylinder, custom maps, etc..) that I really don't have any history to go on to give you a specific answer.  The guys who programmed the ECU for you should be able to tell you what the ECU is expecting.  I would guess that starting at 0.4 or 0.5 with the throttle plate fully closed (idle backed out) should get you at least running, and you can fine tune it from there, but that's just a guess.  Please keep us updated as you progress! :)  And thank you for your business!  

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