2013 TXC 250 starts cold, stalls hot, then won't start.

[Trenchcoat85]

I did pull a plug when the hot start issue was present a few weeks ago. I saw a spark, but can't speak to timing or intensity.

I measured the resistance at the connector leading to the tdc pick-up.

Not sure what you are asking here: Looking for a break in the wiring?

no, I'm trying to move the ohm-meter measurements as close as possible to pulse coil, eliminating connectors and external wiring problems.

...but look for a break in the wiring, of course.

hot re-start: if starting fluid still helps a lot (and the bike runs/idles when hot)... we're still probably looking at a lean condition (or even a "hot-lean condition").

I have a few ideas, but nothing earth shaking.

 

[Marcus G]

Great discussion. Thank you for the feedback

The injector was sent off on Monday to Injector RX in Houston for ultrasonic clean and flow testing. I'll post the report when I get it. I just got an email that it arrived at their facility yesterday. I hope to get it back within the week. I'll clean the throttle body while I'm waiting.

Hi I have a 13 txc250r that is causing me grief with the same symptoms as you bike , did you ever get yours sorted? Thanks Marcus

 

[R_Little]

FYI, I have seen a couple of these pick up coils actually melt from tight single track riding.

I have two stators in a box with melted pick up coils.

Does not look like it happened here though.

 

[durtkillon]

FYI, I have seen a couple of these pick up coils actually melt from tight single track riding.

I have two stators in a box with melted pick up coils.

Does not look like it happened here though.

This bike was a trail/woods bike from Breckenridge, so it most certainly got hot. I'll take a closer look at the flywheel and pick-up. I already buttoned it up, but it warrants a second look. I didn't really know what to look for other than ohm readings and shorting to ground.

I'm going to try to get access to a Husqvarna Service Tool (HST). I'm on the brink of using parts for troubleshooting (stator/pick-up, coil pack, CDI...), so I'd like to hook it up and see what all the sensors are reading at temp. I feel like the fuel delivery system has been ruled out (fuel pressure verified, injector verified). The TB appears to be in good shape and there is no indication of leaks or sticking TB plate. I don't know what else could be wrong at the TB. If the issue is indeed a a/f ratio problem, it must be a bad sensor or the ecu is telling the injector to do something it shouldn't.

If it is the tdc pick-up, not all the data jives. As trenchcoat85 pointed out, I can get it started with starter fluid, but it's not easy. Also, when I bypass the JD tuner, the lean bog comes back when I grab throttle (TPS=0.62v). On occasion, it even flames out. Adjusting the TPS up helps a little, but it's not the solution.

Along those lines, I have conflicting advice on the TPS setting. Ty suggested 0.59-0.62v. Others have said 0.68v (confirmed on other TXC250's). My experience is that higher results in better idle and throttle response. I've had it as high as 0.75v. No setting resolves the hot start issue, however.

 

[Matthew525]

This information was supplied with my HST from Husqvarna.

 

[Matthew525]

i am willing to send you spare parts to try, or put any suspect parts from your bike on my bike to rule anything out you want.

shipping would have to be on your dime though. but im willing to try to help you out!!

 

[Trenchcoat85]

i am willing to send you spare parts to try, or put any suspect parts from your bike on my bike to rule anything out you want.

shipping would have to be on your dime though. but im willing to try to help you out!!

wow! Matt, that's a very generous offer.

would you be willing to send the TB complete [meaning: disconnect the throttle cables and 3 electrical connections (TPS, MAP, condensor), and the fuel line]... maybe leaving the manifold on too? Or were you talking about using Kurt's part on your bike? either way- nice offer.

Kurt- I wrote the following yesterday, but I was kinda waiting for other non-related ideas to pop up (I didn't want to smother other "non-lean running" ideas) before I posted... the last paragraph is the relevant one:
======================================

This bike was a trail/woods bike from Breckenridge, so it most certainly got hot. I'll take a closer look at the flywheel and pick-up. I already buttoned it up, but it warrants a second look. I didn't really know what to look for other than ohm readings and shorting to ground.


I'm going to try to get access to a Husqvarna Service Tool (HST). I'm on the brink of using parts for troubleshooting (stator/pick-up, coil pack, CDI...), so I'd like to hook it up and see what all the sensors are reading at temp. I feel like the fuel delivery system has been ruled out (fuel pressure verified, injector verified). The TB appears to be in good shape and there is no indication of leaks or sticking TB plate. I don't know what else could be wrong at the TB. If the issue is indeed a a/f ratio problem, it must be a bad sensor or the ecu is telling the injector to do something it shouldn't.


If it is the tdc pick-up, not all the data jives. As trenchcoat85 pointed out, I can get it started with starter fluid, but it's not easy. Also, when I bypass the JD tuner, the lean bog comes back when I grab throttle (TPS=0.62v). On occasion, it even flames out. Adjusting the TPS up helps a
little, but it's not the solution.


Along those lines, I have conflicting advice on the TPS setting. Ty suggested 0.59-0.62v. Others have said 0.68v (confirmed on other TXC250's). My experience is that higher results in better idle and throttle response. I've had it as high as 0.75v. No setting resolves the hot start issue, however.

TPS: for now, set it where the bike wants to be. I don't think it's the major issue, and we can reset when we figure out WTF is going on.

You're still running with the JD, right? ...good- maybe we'll remove it once we get the bike running right. The TXC has got the race stuff in it- and it should be a real strong runner without the jd; I think at the moment the jd is just a bandaid for our lean condition. but we need it to make the bike rideable, for your fun and our investigation.

It would be great if you had access to another redhead x-lite ('13-'14 250,310s and maybe TC '12?). The ability to swap out components would be a big-big help. And the stators from early models might work but I've never looked it up. What I'd really like to do is slap a complete Keihin TB in there- probably not a realistic plan though, unless you're good friends with someone close by.

======================================

good luck. (thanks again, Matt)

 

[Trenchcoat85]

hey Matt-
got a picture of the "Self Adaptive Parameter Reset" section handy? I imagine it's cold bike off, battery disconnect/reconnect after pressing the starter button (discharging the condenser) and then start the bike up and let it idle for 5 min without touching the throttle maybe?

 

[Matthew525]

ive got a spare complete throttle body i removed in fall to install an Injectioneering modified and bored throttle body.
all sensors and injector worked when removed and it is complete.

ive got a coil, temp sensor, and some other odds and ends to try that are all known good.

as for the self adaptive reset, there is no specific documentation, but it is a feature of the HST. it is done once connected to bike. You completle the reset cold and start bike and do not touch throttle for 5 minutes. on the HST you can see it changing the throttle % to zero after a few minutes automatically. after the reset it may say about 3% even at 0, but after a few minutes at idle 0 and 100% will be correct.

 

[Trenchcoat85]

ive got a spare complete throttle body i removed in fall to install an Injectioneering modified and bored throttle body.
all sensors and injector worked when removed and it is complete.

ive got a coil, temp sensor, and some other odds and ends to try that are all known good.

as for the self adaptive reset, there is no specific documentation, but it is a feature of the HST. it is done once connected to bike. You completle the reset cold and start bike and do not touch throttle for 5 minutes. on the HST you can see it changing the throttle % to zero after a few minutes automatically. after the reset it may say about 3% even at 0, but after a few minutes at idle 0 and 100% will be correct.

Oh yeah- I remember you mentioning that in another thread a few months back. (the image with the baby in the background).

 

[durtkillon]

Matthew,
I'll give you a call and work something out. With your kind offering, I'm likely to isolate the problem without throwing a ton of parts at the bike. Thank you.

Hi I have a 13 txc250r that is causing me grief with the same symptoms as you bike , did you ever get yours sorted? Thanks Marcus

Marcus, I'm still in the thick of it. Just follow the thread, I'll get it sorted one way or another.

 

[Trenchcoat85]

(I started this before Matthew made his generous offer. His TB would determine if the problem lies there or the manifold I'm hoping. Of course, grab his coil too- since I've been wrong about 4x's now.)

I am still thinking we're dealing with a lean issue. maybe a very small air leak that only affects the lower rpm's or gets slightly worse when warmed up (a crack getting wider?). You mentioned a bad sensor, but really only the MAP and TPI are in play here- the others are not changing values very fast (and the bike does run).

I suppose at the next hot re-start attempt you could unplug the CTS and give it a try though. and then maybe the ATS but I doubt there would be a change.

I'm wondering if the problem came from the factory, and previous owners have been dealing with it too?

I would remove the MAP sensor first. Maybe in its air circuit there is a crack or the seal is bad. I cannot tell how the circuit goes- seems like the port is on the upstream side of the throttle plate (and then maybe goes around the throttle plate too? doesn't make sense to me). clean it out, inspect for cracks etc. take a look at the o-ring.

Next I'd take the intake manifold off and inspect it thoroughly- especially the mating surface with the cylinder. Our leak, if it exist, would be pretty small. The rubber used on Husky manifolds has been known to crack also.

The idle air bypass (cold start) circuit deserves a hard look. If air was getting in here downstream of the MAP sensor, it would be undetected. Maybe try my tape trick- although only the downstream hole would need to be covered, I think.

The throttle body itself might have a problem. I noticed on other similar tb models that there is a vacuum port on the very bottom (under the condenser perhaps) just downstream of the throttle plate. I'm thinking our tb's are not drilled out here, but take a look. Actually, anyplace air could get by without being measured by the MAP sensor would be a good place to inspect.

Besides the throttle stop on the bell crank (that you noted was previously "adjusted") there is one on the actually throttle plate also- has that one been messed with? IIRC, you said that no air was passing the throttle plate after you re-adjusted?


And if none of this helps, try Matthew's coil; and then lets do a compression test. Although I cannot figure out what might be happening in the top end that would cause these symptoms.

 

[durtkillon]

Well I think I nailed it down.

Swapped the TB out with Matthew's known good TB and it ran fine, hot start and all. The TPS Matthew sent came in at 0.68 volts. I left Matthew's TB on the bike and swapped my injector and the hot start issue came back. The injector appears to be failing at temp, but Matthew's injector does not.

Of course I'm telling the abbreviated version. I swapped the CTS, MAP and TPS first, but did not get a signal.

The injector testing I paid for must not actually get the injector hot. My guess is the solenoid is getting stuck and sending too little fuel when hot.

I need to take it for a ride to be 100% sure, but it's behaving better than it ever has. Matthew, my friend, thank you VERY MUCH! Trenchcoat85, high 5 to you too.

 

[Trenchcoat85]

holy shit- this is great news! if it is a problem with the injector, also let your testing company know. swear to gawd... i just finished typing the following (& you saved my hair)-

Hey, after the test with Matthew's TB or the individual tests (MAP circuit, throttle bypass, tb inspection, manifold inspection) I have another unrelated idea:

Look extremely hard at the cam timing. On some models there can be a one tooth error, and it's very hard to detect. The bike might start okay cold, maybe run okay... but hot starts are very hard.

Maybe someone back in the day got the timing off on your bike and never detected it.

I've never heard of this on xlites though; mostly big blocks. but it's worth a hard look- especially if the above intake test fail to find a problem.

I am starting to pull my hair out.

 

[Trenchcoat85]

...and I think your injector is fu'd when cold too; just not as bad as when hot... and the JD unit still can compensate enough.

when you get a new injector, take the jd out and see how it runs.

 

[durtkillon]

I'm declaring the hot start issue resolved after my test tide today There were two key takeaways:

1. The high compression resistance to starting was the resolved by tightening the decompressor exhaust valve clearance from 0.280mm to about 0.180mm. My final setting was 0.15mm, but it had measurable improvement beyond 0.18mm.

2. The injector, though professionally cleaned and tested, was failing. This resulted in low power (obvious to me after the repair, not before because I bought the bike with this symptom), a tendency to stall, particularly when hot and a total inability to fire up during start at medium or high temps, even though the starter would turn over fine. I also observed a lean bog or occasional flame out when grabbing 3/4 throttle.

What is not clear is whether I could have diagnosed the bad injector better. I did not do the spray test in a jar or on cardboard because I trusted the professional results from Injector RX. I may try a cardboard test this weekend with the bad injector

 

[Trenchcoat85]

I'm declaring the hot start issue resolved after my test tide today There were two key takeaways:

1. The high compression resistance to starting was the resolved by tightening the decompressor exhaust valve clearance from 0.280mm to about 0.180mm. My final setting was 0.15mm, but it had measurable improvement beyond 0.18mm.

2. The injector, though professionally cleaned and tested, was failing. This resulted in low power (obvious to me after the repair, not before because I bought the bike with this symptom), a tendency to stall, particularly when hot and a total inability to fire up during start at medium or high temps, even though the starter would turn over fine. I also observed a lean bog or occasional flame out when grabbing 3/4 throttle.

What is not clear is whether I could have diagnosed the bad injector better. I did not do the spray test in a jar or on cardboard because I trusted the professional results from Injector RX. I may try a cardboard test this weekend with the bad injector

I'm in total agreement- without Matthew's hardware that would have been hard to diagnose. And I still can't figure how how the injector screwed up. I don't understand what the JD was doing (longer duration spray- yes) that was overcoming the defect in the injector.

BTW, is the JD still in? how does it idle, run wide open, throttle response with the new injector (I am assuming a new injector)?

(glad you came around on the valve clearance. in fact, I even consider 0.15mm slightly loose for an OHC motor)

I would be interested in hearing how the bad injector does in your test- come back and let us know.

It's nice to solve one of these head-scratchers every once in a while.

 

[mariosav34]

Found this thread a couple of weeks ago but didn't read it through (only first few posts, DOH!) and then lost it... I only fully read it the same day I received my new injector for the exact same issue on my '14 TXC310R haha Could've saved about a week had I found it earlier... Anyways, just wanted to share my experience and answer your question regarding what was wrong with the injector, or at least mine.

I had the exact same behavior as described here, ran fine when cold, but within 15min even of idling, it would start to sputter and die eventually, also had a lot of popping at decel and it was hard to start when hot, though it did start every time after a min or so. So maybe not exactly the same but very similar.

Here's a video of how it ran when hot at idle:

So long story short, I thought it was a fuel pump or injector and as everyone here thought the bike was running lean due to pump going bad and not mantaining pressure or clogged injector. The difference is I tested the setup myself at the bench, plugged in a pressure gauge in line to the injector after the regulator and used the 12v batt to both activate the pump and actuate the injector. Initial results were inconclusive as I was focusing on the pump which was holding steady 50psi for 20+min and the injector spray pattern looked healthy.

It was only after I looked at the injector when NOT spraying fuel that I noticed the issue... Leaky injector, see below video I recorded of this:

It only happened AFTER I actuated it a few times and it would leak for a min and then stop leaking (with pump still on). So the bike didn't start and would sputter because it was too rich, not too lean. Also not properly atomized.

Anyways, I replaced the injector with a new one and the issue went away! Now I'll send my injector out for cleaning/checking to see if it was debri preventing it from closing (the red oring was in bad shape/flaking)

Hope this helped fulfill your curiosity!

 

[Trenchcoat85]

wow. great vid! how long would it keep dripping- I'd guess down to the point where the pressure was reduced enough.

Don't forget that Kurt had his bad injector cleaned & flow-tested... and it was still bad. This still amazes me; it also reminds me that just because something is stamped "quality inspected" or whatever, still could be defective.

how much was the new injector?

(ps- about your screen name: any political meaning to it? I am referring to Mario Savio, the famous '60s free speech activist)

 

[mariosav34]

It only dripped for a minute after being actuated, and it was actually with the full 50PSI at all times (even when it stopped dripping) because the pump was powered directly by an ext battery.

Don't forget that Kurt had his bad injector cleaned & flow-tested... and it was still bad. This still amazes me; it also reminds me that just because something is stamped "quality inspected" or whatever, still could be defective.

Yeah, and in terms of flow and spray pattern, mine looked fine so I'm guessing they did not check for leaks after actuating the injector. Maybe they checked for leaks from a fully unpowered injector or after it sits for a couple of minutes, in which case mine did not leak at all (see the beginning of the video where there's no dripping).

New injector was $83 with free shipping from Motosport.com

(ps- about your screen name: any political meaning to it? I am referring to Mario Savio, the famous '60s free speech activist)

Haha, no political reference here, just the initials for my 3 last names.