2012+ ignition coil failure ? Widespread problem ?


17 replies to this topic
  • MidlifeCrisisGuy

Posted November 15, 2014 - 02:29 PM

#1

It snowed last week.  Its a bit below freezing today.  I was prepping my bike for winter riding.  I decided to fire it up because I've never it run it when its this cold out.   It started perfectly on second kick.   It idled 20 seconds and died.

 

I kicked it about 15 times.  It seems like it wants to start, but it won't.

 

Pulled the spark plug.  Its wet, its getting fuel.  Injector must be working, fuel pump must be working, voltage regulator must be working, ECU must be working.   The injector needs all of these to work in order to deliver fuel.

 

Checked for spark.  There is none.

 

Put in a new spark plug for the fun of it.   It won't start.

 

Checked the resistances on the ignition coil. Owners service manual, page 9-71.  Primary side - 3.75 ohms.   Right in the middle of the acceptable range.   Secondary side - 20.4 Kohm, to either primary pin.  Acceptable range is 10.71 to 14.49 K ohms.   Failed ignition coil ?  Service manual calls for replacement if its outside the acceptable range.

 

Could someone test their ignition coil to see what they get ?   

 

Called the dealer.  None in stock.  There is 1 in Wisconsin.   They are back ordered to Japan ?  3 to 4 weeks to get one ????    Is there some sort of problem with the ignition coils on these bikes ?  FWIW, the FI YZ250F and YZ450F use the same coil.  (Part number 33D-82310-00-00)

 

Last year my bike started on the first kick when hot.  This riding season my bike went from needing 1 kick all the time when hot to sometimes needing 2, maybe 3.

 

On my last ride, a couple times it needed several kicks.  Very unusual for my bike.  This issue has been building for a while ?

 

I'm darn lucky this thing didn't stop out on the trail.  Prior to this its been 100% reliable.

 

I'll update this thread as the situation unfolds.


Edited by MidlifeCrisisGuy, November 15, 2014 - 02:40 PM.


  • alh583

Posted November 15, 2014 - 06:25 PM

#2

there is always eBay if there that far back ordered



  • MidlifeCrisisGuy

Posted November 15, 2014 - 07:17 PM

#3

there is always eBay if there that far back ordered


Very true. I see there are a couple for sale, some of which are new.

  • sherco67

Posted November 15, 2014 - 07:30 PM

#4

Think I have a new one in package in attic from 09 WR450F if able to work?



  • MidlifeCrisisGuy

Posted November 16, 2014 - 07:52 AM

#5

Think I have a new one in package in attic from 09 WR450F if able to work?


Nope. The FI coils are different electrically (primary resistance is much higher) and not interchangeable with the previous (CDI) coils.

Thanks for the offer though.

Its bumming me out that i missed riding today because of this.

  • GuyGraham

Posted November 16, 2014 - 08:04 AM

#6

Close the plug gap down to about 0.3mm

This will lesson the voltage requried to fire the plug - this will confim if HT coil is failing

 

Normally they go open circuit when they fail, but failure is gradual which starts with a hot misfire slowly getting worse



  • MidlifeCrisisGuy

Posted November 16, 2014 - 12:07 PM

#7

I decreased the plug gap down to 20 thou.   I can get a single spark on about every 5th kick.  I put the plug in to try to start the bike, but it won't fire.

 

I increased the gap to 30 thou.  Bigger gap = hotter spark.   I can get a single orange spark on every 10th kick.  It won't fire with it.

 

There is no "snap" sound to the spark when it happens.  Its not like a lawn mower spark plug that goes snap, snap, snap, snap when it fires.



  • kingjewells

Posted November 16, 2014 - 07:29 PM

#8

Hello, I also have a 2012 WR450 and had the same trouble in January 2013. Please check your battery first. You should have at least 13.7 volts on a fully charged battery.  If your battery is good, check under the left # plate and make sure the ECU hasn't slipped down in the rubber mount and allowed the multiple wires coming out the bottom of it to chaff and short out. I Hope its just a bad battery. If not I do have a voltage regulator laying around if you think that would help. 


Edited by kingjewells, November 16, 2014 - 07:40 PM.


  • vlxjim

Posted November 16, 2014 - 09:48 PM

#9

The OP has no battery.



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  • MidlifeCrisisGuy

Posted November 16, 2014 - 10:16 PM

#10

Hello, I also have a 2012 WR450 and had the same trouble in January 2013. Please check your battery first. You should have at least 13.7 volts on a fully charged battery.  If your battery is good, check under the left # plate and make sure the ECU hasn't slipped down in the rubber mount and allowed the multiple wires coming out the bottom of it to chaff and short out. I Hope its just a bad battery. If not I do have a voltage regulator laying around if you think that would help. 

 

Thanks for the suggestions.  I have removed the battery and starter from my bike.   I'll hook up a remote battery to it tomorrow in order to rule out the voltage regulator.

 

What was the root cause of the problem on your bike ?

 

Regardless of what else may be wrong with my bike, the ignition coil secondary resistance is outside of spec, so it needs to be replaced.   I'd be very interested to hear what the secondary resistance is on some other bikes, especially those with the hard starting issue.

 

I'm also going to look into why stock is so low on ignition coils.  I'm wondering if there has been an upgrade to them.



  • GuyGraham

Posted November 17, 2014 - 11:38 AM

#11

Don't get hung up on resistance values as they are more of an indication than an absolute

Fair enough if you have open circuit, but a reading that is a few KOhms over top limit  doesn't mean you have a failed coil

 

Have you check the source coil resistance on the stator?

 

WRT FI coils not being interchangeable with older non FI bikes, I have never found this

Indeed, a common mod for the DRZ is to convert it coil-on--stick to do away with the HT coil (like the 07-11 WR) using a plug cap from a GSXR.

 

The coils don't care if the bike is FI or not

They take low voltage from the source coil and convert it into high voltage - its nothing more than a transformer in reverse

 

I'd take up the offer of trying the 09 WR coil on the stick


Edited by GuyGraham, November 17, 2014 - 11:42 AM.


  • MidlifeCrisisGuy

Posted November 17, 2014 - 12:39 PM

#12

Connected up a fully charged battery (12.9V) to my bike.  Fuel pump runs and shuts off normally.  Same intermittent/weak spark.  Installed the plug.  It won't fire.



  • MidlifeCrisisGuy

Posted November 17, 2014 - 12:50 PM

#13

Don't get hung up on resistance values as they are more of an indication than an absolute

Fair enough if you have open circuit, but a reading that is a few KOhms over top limit  doesn't mean you have a failed coil

 

Could be true.

 

 

Have you check the source coil resistance on the stator?

 

 

No, but other signs point to "it" being OK. (It = crankshaft position sensor.)  The injector is firing when I kick it, for example.  The crankshaft position sensor only provides the timing signal to the ECU on these bikes.  With the bike connected to a battery as I did earlier today, the entire alternator system is taken out of the troubleshooting loop.

 

 

WRT FI coils not being interchangeable with older non FI bikes, I have never found this

Indeed, a common mod for the DRZ is to convert it coil-on--stick to do away with the HT coil (like the 07-11 WR) using a plug cap from a GSXR.

 

The coils don't care if the bike is FI or not

They take low voltage from the source coil and convert it into high voltage - its nothing more than a transformer in reverse

 

I'd take up the offer of trying the 09 WR coil on the stick

 

I looked into their compatibility before I relocated the coil on my bike.  The pre FI (CDI) coils have a primary resistance of about 0.5 ohms IIRC.   The FI coils have a primary resistance of ~3.5 ohms.  The FI coils are probably fired my a low side MOSFET and clamp circuit within the ECU that is designed for 3.5 ohms.   If you connect a coil with a 0.5 ohm primary, that part of the circuit is going to draw 7x more current.  That is asking for trouble.  

 

Being that I appear to have eliminated most of the other variables in the ignition circuit, ie the bike has good DC power, a signal from the crankshaft is firing the injector, the ECU talks with the programmer just fine, etc, and the coil tests out of spec, I am going to replace it as a first step.

 

The possibility exists that there is a break in the wiring harness somewhere.  I'll check for that if the new coil doesn't solve the issue.   No sense in tearing apart the wiring harness when I know the coil is out of spec.


Edited by MidlifeCrisisGuy, November 17, 2014 - 12:51 PM.


  • MidlifeCrisisGuy

Posted November 17, 2014 - 03:10 PM

#14

Reader's Digest update: the coil is fine.

 

I measured the secondary ignition coil impedence incorrectly.  I didn't remove the plug cap.  It screws off.   I was in a big rush to get the bike running on Saturday for my ride on Sunday and I missed the part about removing the cap.

 

The correct coil secondary resistance is 11.1 Kohms, which is good.   The plug cap resistance is 9.3 Kohms, which is probably OK.   The manual says "10Kohms", with no range.   They are probably suggesting you don't want to see an open circuit, nor a short.  9.3K + 11.1K = 20.4 Kohms, which is what I was reporting before. 

 

So the ignition coil is fine.

 

 

I checked the crankshaft position sensor (step #6) and its fine as well.  268 ohms.

 

I spent a bunch of time checking the harness and switches and connections.  Steps #7, 8, 9, 10)   I found no visible breaks or wear.  FWIW, my harness is completely stock except for unplugged devices and I cut a few unused connectors for devices under the number plate off.  When the various switches and relays are removed, I only needed to add back 2 jumpers and add a single ground point.

 

I think the lean angle sensor is defective, but I'm still verifying that.  At one point in testing I got 10 good sparks in a row and the bike fired and died.



  • vlxjim

Posted November 17, 2014 - 03:20 PM

#15

Check the kill button and the wiring for it. Seen that cause problems like you are having. Try swapping the ECU. And check the piston return spring too.



  • MidlifeCrisisGuy

Posted November 17, 2014 - 03:26 PM

#16

Its not the lean angle sensor.

 

 

Check the kill button and the wiring for it. Seen that cause problems like you are having. Try swapping the ECU. And check the piston return spring too.

 

 

I did check it.  The button itself is good.   Might be a problem from the button connector in the harness though.

 

Piston return spring ?   What is that ?

 

The GYTR programmer is not showing any trouble codes.  I'm about to hook up the FI tool.

 

For anyone fighting an ignition problem that has the FI tool, turns out you can activate the ignition system via the FI tool.  The procedure is listed on page 9-43 in teh FUEL INJECTION section !  FI tool can fire the plug 5x and check for various issues.   Wish I would have found this earlier.


Edited by MidlifeCrisisGuy, November 17, 2014 - 03:29 PM.


  • kingjewells

Posted November 18, 2014 - 09:30 AM

#17

Don't get hung up on resistance values as they are more of an indication than an absolute

Fair enough if you have open circuit, but a reading that is a few KOhms over top limit  doesn't mean you have a failed coil

 

Have you check the source coil resistance on the stator?

 

WRT FI coils not being interchangeable with older non FI bikes, I have never found this

Indeed, a common mod for the DRZ is to convert it coil-on--stick to do away with the HT coil (like the 07-11 WR) using a plug cap from a GSXR.

 

The coils don't care if the bike is FI or not

They take low voltage from the source coil and convert it into high voltage - its nothing more than a transformer in reverse

 

I'd take up the offer of trying the 09 WR coil on the stick

My problem was the ECU slipped down in the rubber mount and allowed the multiple wires coming out the bottom of it to chaff and short out. My fix was that I ended up replacing the wire harness because I was lucky to have one available.



  • MidlifeCrisisGuy

Posted November 24, 2014 - 09:07 AM

#18

Update.  

 

I traced the spark issue to an issue with the lean angle sensor.

 

The starting problem after that was isolated to have C1 set to 8 as described in this thread.

http://www.thumperta...starting-issue/

 

I learned an awful lot about troubleshooting these bikes in the process.  They are actually very easy to work on if you have the FI tool and you follow the right steps.  For most any no start condition, I recommend

 

1) check parameter d:61 for error codes and deal with them appropriately.  Reset codes and make sure they don't reappear.

2) pull the spark plug and run parameter d:30.  This fires the plug 5x and checks the entire ignition circuit.  Observe a good strong spark at the spark plug.

3) run parameter d:36, with or without the subframe and air box installed.  This fires the injector 5x and checks the entire injector circuit.  Observe that fuel is spraying into the throttle body.

 

This sequence should isolate 90% of the issues.  The Owners Service Manual is very good once you find something definitive, though relevant troubleshooting information is a bit scatted between the FI section and the Ignition section.   Specifically, even if you are troubleshooting an ignition issue, start in the FI section. 

 

I hope this helps someone.


Edited by MidlifeCrisisGuy, November 24, 2014 - 09:08 AM.





 
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