2015 CRF250R ECU QUESTION

MxMobster471
Over the weekend we managed to do some troubleshooting with my bike and it has left me with following question before ordering the new part.

After testing the the majority of the wiring we found one with no continuity between the ground and injector plug. The manual says this is the symptoms of a faulty ECU. Has anyone ever experienced this? Does this sound logical to you electronically savvy fellas?

I also wanted to inquire about the option of testing with a fellow riders ECU. He has the same bike, but his ECU has been mapped. Would it in anyway, shape, form or fashion put his in jeopardy to try to fire mine up with his connected? I can't afford two ECU's.

Side note: The bike will not start without placing the gas or spraying ether directly into it. So the injector has been suspect for some time. Just now got around to being able to play with it some.

Thanks in advance,
Sidney
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Paw Paw 271
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Paw Paw 271 2/27/2017 9:17am
2/27/2017 9:17am
If it will fire up with fuel added, then I really don't think it is the ECU. It sounds more like the injector or fuel pump to me.

Paw Paw
MxMobster471 2/27/2017 9:35am
2/27/2017 9:35am
We've tested the pump to assure that it is fully functional. We have also replaced the injector.

Sorry for not including that in the original post.
FGR01
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FGR01 2/27/2017 12:57pm
2/27/2017 12:57pm Edited Date/Time 2/27/2017 12:58pm
Paw Paw 271 wrote:
If it will fire up with fuel added, then I really don't think it is the ECU. It sounds more like the injector or fuel pump...
If it will fire up with fuel added, then I really don't think it is the ECU. It sounds more like the injector or fuel pump to me.

Paw Paw
Actually, it could be the ECM. There is circuitry through the ECM that controls the voltage for the pump and injector. My buddy had this exact same problem with his CRF450. Would not start but if you sprayed ether in the carb it would. Ended up being a bad ECM.

MxMobster471 2/27/2017 3:49pm
2/27/2017 3:49pm
Paw Paw 271 wrote:
If it will fire up with fuel added, then I really don't think it is the ECU. It sounds more like the injector or fuel pump...
If it will fire up with fuel added, then I really don't think it is the ECU. It sounds more like the injector or fuel pump to me.

Paw Paw
FGR01 wrote:
Actually, it could be the ECM. There is circuitry through the ECM that controls the voltage for the pump and injector. My buddy had this exact...
Actually, it could be the ECM. There is circuitry through the ECM that controls the voltage for the pump and injector. My buddy had this exact same problem with his CRF450. Would not start but if you sprayed ether in the carb it would. Ended up being a bad ECM.

Thanks for the responses guys. It's refreshing to know its at least a possibility and the manual hasn't sent me on another snipe hunt. (Just yet)

Any clue as to if it would cause issues for mine or my buddies mapped ECM just to try and fire it up real quick?

The Shop

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Paw Paw 271
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Paw Paw 271 2/27/2017 3:59pm
2/27/2017 3:59pm Edited Date/Time 2/27/2017 4:01pm
I don't see much of a risk in using the mapped ECU for a test start up. I would not run it long however as we have no knowledge of the mapping in the unit.
Also don't forget to check the TPS sensor. If it is not working ( or set correctly) it can also shut off fuel flow.

Paw Paw
MxMobster471 3/1/2017 9:38am
3/1/2017 9:38am
Thanks for your responses fellas.

Been a busy week thus far. I will update with the end result of the ECU test.

Cheers.
gharmon
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gharmon 3/23/2017 6:43pm
3/23/2017 6:43pm
Ok we got an new ECU and tried it. According to our testing via the service manual it was the ecu, NOT. Still same ole shit. It everything works up until the injector. The infector spurts out a tiny bit of gas if you kick it over with the injector hanging out the side of the bike.

So, the one thing I didn't want to do was jus throw money at but it seems we have. We have a new injector and a new ECU. What's left that controls the injector's spray pattern/amount? The TPS, condenser, rectifier? Per pawpaw I was thinking of buying a new TPS sensor but it appears it's only available as a whole unit with the throttle body? Can I buy it separately? Anyone got any idea what part I should replace next. The OP is my son if there's any confusion..lol
walent215
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walent215 3/23/2017 8:34pm
3/23/2017 8:34pm
We had to change the filters on our 13 and 15 crf250s ....they both were very hard to start and had i think 60-80 hours on them .
gharmon
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gharmon 3/29/2017 7:44pm
3/29/2017 7:44pm
No Paw Paw we haven't tested the TPS. We don't have the part that gives it batter power to test it but I found a way to make a tester on TT. It has instructions for using an old cell phone charger as most of those are of the 5 volt range you need to test it. Unless you know of a better way to test the tps???

It was mentioned but we used a stator from a working bike and it made no difference. So, we've eliminated the stator, ecm, and injector. We also changed the sock on the fuel filter. I dont' think the pump is a problem. You can just leave the fuel line plugged into the tank and undo the end at the injector and hang the line out the side of the bike and kick it over and copious amounts of fuel come flowing out.

It looks like out next try is the TPS but I'll entertain other ideas. Paw Paw have you ever seen a TPS go bad on one of these bikes?
gharmon
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gharmon 4/10/2017 6:43am
4/10/2017 6:43am
I just wanted to update everyone on what ended up being our problem. Like in previous posts we had check several different items. We replace the injector, ecu and spent countless hours fooling with this thing.
It ended up being a bad fuel pump which we thought we had eliminated as a possible cause. I had undone the fuel line and kicked the bike over and it would pour out plenty of gas as you kicked it, indicating that it was working. I had even hooked the pump up to an electrical source and watched it shoot fuel out the pump.

Per Paw Paw, I had rigged up a device to check the tps (thanks TT for the instruction on the homemade tester) and it checked out fine. We had even purchased one(throttle body as tps is only available that way) ahead of time. Well in the midst of removing the tank and all the stock tank pump just started pouring fuel when removed. I was like well hell the check valve just took a shit. So for f@cks sake lets throw this other tank we have over here on the bike (our friend had just dropped off his 2012) and low and behold the damn thing cranked.

Had that check valve not taken a crap I would not have found this problem.

I just wanted to update everyone as I hate when you are reading a thread and the ending never gets posted.

Thanks guys for all the advice.

Gerald
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jaredkeller96
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jaredkeller96 4/15/2017 11:42am
4/15/2017 11:42am
you can cross reference the TPS on those throttle bodies that way you don't have to buy the whole unit. start with the stator. CRFs get really hot and can cause the solder in the stator to come loose. get a new stator then epoxy the contact points
Nate_Morrow185 11/10/2021 12:06pm
11/10/2021 12:06pm
gharmon wrote:
I just wanted to update everyone on what ended up being our problem. Like in previous posts we had check several different items. We replace the...
I just wanted to update everyone on what ended up being our problem. Like in previous posts we had check several different items. We replace the injector, ecu and spent countless hours fooling with this thing.
It ended up being a bad fuel pump which we thought we had eliminated as a possible cause. I had undone the fuel line and kicked the bike over and it would pour out plenty of gas as you kicked it, indicating that it was working. I had even hooked the pump up to an electrical source and watched it shoot fuel out the pump.

Per Paw Paw, I had rigged up a device to check the tps (thanks TT for the instruction on the homemade tester) and it checked out fine. We had even purchased one(throttle body as tps is only available that way) ahead of time. Well in the midst of removing the tank and all the stock tank pump just started pouring fuel when removed. I was like well hell the check valve just took a shit. So for f@cks sake lets throw this other tank we have over here on the bike (our friend had just dropped off his 2012) and low and behold the damn thing cranked.

Had that check valve not taken a crap I would not have found this problem.

I just wanted to update everyone as I hate when you are reading a thread and the ending never gets posted.

Thanks guys for all the advice.

Gerald
Gharmon. I am having this same issue with my fuel. Where is this check valve you speak of? Did this allow the bike to fire?

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