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2012 500 exc starting issues

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I don't know much about the throttle body on FI bikes but does it have a some kind of throttle stop besides the Idle adjustment? maybe by cracking open the throttle for an easier start would indicate it moved?

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so, what is this Initialization run I found in my service manual? maybe that needs to be run on the OP's

Does the diagnostic tool need to be running or can it be performed without it?

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15 hours ago, gitenby said:

I don't know much about the throttle body on FI bikes but does it have a some kind of throttle stop besides the Idle adjustment? maybe by cracking open the throttle for an easier start would indicate it moved?

You might be on to something. Thats a good possible direction to check because im not the first owner, and this problem came with the bike and i dont really have a way to know if someone messed with the throttle mechanics.

Manual adjustments for the TB are as follows - 

 

307266.png

 

The first one is the TPS Voltage wich i allready figured out and setted to the best possible area for my bike (0.625) but i dont kow or understand what are "Signal ATP" values as the second adjustment says - and how do i test it.

If someone have an idea , shoot.

Edited by Earthmover

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2016 model

 

I believe that just means throttle plate completely closed.

 

Now Ive heard , but never tried, as Ive never had a starting issue.  

That one KTM tech was backing out the throttle plate stop. set tps to .60, then turn the throttle plate stop, out to .665v, have no ideal how that works, that was with the euro map.

 

but you might look at the throttle plate stop and see if the yellow Loctite has been broken, its normally pretty obvious as its blobbed on there. its on the right side of the throttle body at the bottom , behind the throttle wheel.

Edited by Spud786

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23 hours ago, Spud786 said:

Now Ive heard , but never tried, as Ive never had a starting issue.  

That one KTM tech was backing out the throttle plate stop. set tps to .60, then turn the throttle plate stop, out to .665v, have no ideal how that works, that was with the euro map.

So he setted the TPS to 0.6 in closed position, and then he did what to get 0.655? you mean that he did 2 adjustments - 1 setting th TPS to 0.6V and then open the throttle plate with the stopper screw until the TPS gave 0.665? after that he setted the TPS back to its preffered values?
If it does and i did understood you it makes some sence - if 0.6v is setted with fully closed throttle plate as a baseline, and he sets the plate stopper screw for the TPS to give 0.665v, he basicly sets the throttle plate "closed/idle position" angle and openes air passage.

That can be a good thing to try, because when i help the bike with the a bit of throttle (alowing more air in) its starts quicker

Edited by Earthmover
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Yes two adjustments,  

He backed out the throttle stop screw, so it didn't interfere with the throttle plate fully closing, then set tps to .60 volt. then turned the throttle stop in till read .665v. That was also with the euro map, don't know if it was the base euro map or a modded Euro map.

Ive never tried it, but I remember the post from years back, and went back and looked it up. 

 

 

 

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 Either way its a good baseline, i can start with 0.665, set my tps back to 0.625 and test. If its better but not perfect i can try 0.005 incraments up or down and test again to see if something is getting better.

Ill allso test the tps voltage drop when ill turn open the stop screw so ill have a number to get back to (0.625 that i have now minus the voltage drop that ill get when i open it in thw first time) if things arent getting better or even getting worse.

A question while im at it - i dont have a keyswitch and im setting my tps with pulses on the starter button. do you know how can i make it stay on for these adjusments?

Thank you for looking it up and bringing these findings.

Edited by Earthmover
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OK here's an update.

last week iv opened the plastic cover on the throttle body to start looking at the stopper screw (was locked in place with the original yellow paint on it) and see where its at. surprisingly it wasnt even touching the plate lever mechanism when its fully closed - wich means it didnt did nothing and the throttle plate was fully closed each time the throttle was free. I was happy to find that because now i have a direct suspect for this issue.

Went ahed and connected the multimeter to the tps, setted it to 0.6v and started closing the stopper screw to 0.665v target value. after that i setted the tps back to its original place at around 0.63 , started the bike and setted the rpm to 1950ish.

After that iv tested how it starts for a few times and it seemd it still need some help, so iv added 0.015v to the throttle plate position thru the tps and resetted the tps again to its original value. tested again and wasnt better but a bit worse so i went back 0.015 to the original place iv setted it from the beginning.

Since than i rode 2 offroad rides in 2 different days, at the first day it was way better than before - bike is actually starts after 3-4 rotation but not consistently - it still have sometimes trouble to start up. a BIG bonus iv got is that the bike got absolutly BEAST powerwise - its never been that strong since i have it no matter where iv setted the tps before. absolutly a different kind of power - power wheelies in 3rd gear if im not cautious about crancking the throttle - never done that before.

Anyway yesterday iv went for a second all day ride and it still isnt consistent - somtimes it starts ok (less times from my previous ride) and sometimes it cranks a lot. 

I do have backfires that tells me the tps isnt in its idle place yet so after ill fine tune it a bit more it might help. Ill allso didnt tested yet if it started how its starts with the choke on at the same places its having troubles starting without it (warm engine) but maybe i should. another option is that maybe 0.665 throttle plate psition is too much and i should reduct 0.015 to 0.650 and see how it goes , but im hoping to set the tps this week and report if all in all its solved or improved the problem. anyway iv earned more power in the process so im happy with what i did so far either way.

Edited by Earthmover

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(((Went ahed and connected the multimeter to the tps, setted it to 0.6v and started closing the stopper screw to 0.665v target value. after that i setted the tps back to its original place at around 0.63 , started the bike and setted the rpm to 1950ish.)))

 

The idea was , with throttle plate screw backed out, set tps to .60v, then turn throttle stop screw to a reading of .665v and leave it there.

 

Your defeating the purpose , resetting the tps after that  , unless it doesn't work right at .665

 

 

BTW which map do you have?  

Edited by Spud786

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Read again - the stopper screw was allready backed out so i didnt had to back it out. the tps was set to 0.6v WITH fully closed throttle plate without stopper screw touching it, staring this proceedure

Edited by Earthmover
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I understand that, but you said after achieving .665 . you reset the tps to .63, did you try .665?

 

what map is this?

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My bike runs on a euro map.

And no i didnt tried 0.665 because it doesnt make sense to me. the whole process seems to be used for fine tune the throttle plate gap itself mechanicly with the help of the tps as a tool - not as a part of the process. thats why iv setted it back to the 0.63 it was from the begining after the plate itself was setted.

If you still think its worth trying 0.665 please explain why you think so, i have no problem trying that and ill probably  will just for us to know the outcome. as far as i understand backfires on this bike accures when its too rich - wich means i need to lower the tps voltage not bumping it up.

Edited by Earthmover

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Okay, are we on the same page now, I understand your throttle stop wasn't touching, but once you set the tps to .60volt with no screw touching, and then turned the stop screw out to achieve .665.  Halt there and see how it do, before anything else.  That was the original method posted, of which Ive not tested myself.

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Ok ill bump my tps to 0.665 as the throttle itself didnt moved since the 0.665 setup and see how it does.

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20 minutes ago, Earthmover said:

My bike runs on a euro map.

And no i didnt tried 0.665 because it doesnt make sense to me. the whole process seems to be used for fine tune the throttle plate gap itself mechanicly with the help of the tps as a tool - not as a part of the process. thats why iv setted it back to the 0.63 it was from the begining after the plate itself was setted.

If you still think its worth trying 0.665 please explain why you think so, i have no problem trying that and ill probably  will just for us to know the outcome. as far as i understand backfires on this bike accures when its too rich - wich means i need to lower the tps voltage not bumping it up.

Backfiring or severe popping is normally from a closed throttle lean condition ,  but if you were trying the .665 method as posted, you didn't really try it, As you re-ajusted the tps before trying.

Edited by Spud786

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If the .665 is horrible, You might try, just backing off the stop screw, without manually readjusting the tps, as the set screw will be taking the tps Down as your closing the throttle plate, as then you might halt the screw at .63 and try that.

But it would be of interest, .665 result

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Very curious to see what is causing this problem. Interesting that it starts so well when cold. Perhaps its something heat related ? ECU getting hot ? Its too bad you didn't have another ECU to try to rule that out.

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5 minutes ago, jdepp said:

Very curious to see what is causing this problem. Interesting that it starts so well when cold. Perhaps its something heat related ? ECU getting hot ? Its too bad you didn't have another ECU to try to rule that out.

My next and last suspect is the injector. The reason its a suspect is beacuse if i shut down the bike when its warm and start it up again after 10-20 seconds itll fire right up. If ill start the bike after more than 1 minut than the long cranking accures, wich tells me that maybe the injector is leaking and flooding the cylinder while theres pressure in the fuel rail (warm bike - prussure in the system) and the engine was off for more than 1 minute. Iv tested it outside the bike and it performs well and hold pressure, but who knows.

Soon ill try again what we dicussed here and will bring the resaults.

Edited by Earthmover

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If you think it may be flooding....why don't you re-create the scenario where you think it may have flooded and then quickly pull the spark plug.

If the plug is dry and does not smell strongly of gas...then you're probably not flooding.....if it is wet and reeks of gas...BINGO!

Just a though....easier than pulling the injector.

PS...I have the same year bike (2012)...but its a 350.  My injector did start to leak...(damaged gasket...the orange one))...but it was very easy to tell because gas was pouring out of the injector and dripping all over the lower crankcase. It was painfully obvious. 

But I guess if your thinking that maybe its leaking out the actual injector nozzle (injector not closing)...then that's a different story.  If that's the case, then your fuel system would loose its pressure fairly quickly I would think. Maybe try pressurizing the system (tap the start button) and then wait 2 or 3 minutes.  Then try tapping the start button again....does the pump come on again for 3-4 seconds??

If it does come on again...then maybe you are loosing pressure thru a non-closing injector....if it doesn't come on...then you are holding your pressure and therefore are unlikely to be leaking.

Might be worth trying these things because at least in the case of my 350...pulling the injector was a bit of a chore...had to raise the whole rear sub-frame to get access.

 

Good luck....it's a real PITA problem you have.

 

 

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