Cranks but not running, intermident issue

Energy One

roedog

Member
I have an 03 Mastiff, it died on me the first time this past weekend. I felt it somewhat cutting out going down the freeway, but just thought it was a hicup. Well as soon as I got to the off ramp the Dog died I coasted off the freeway. I had to get it towed home to make it short $108. It was cranking over fine after it went down, until I killed the battery. But it would not run? I checked the spark all good, checked errors on the module under the seat, nothing. I verified I get a red light when I push the start button. So crank sensor seems ok? I left tender on the battery overnight, cause it only had 12.3VDC. Next day I had it up to 13.4VDC, and started it up and what you know it runs. Battery voltage increased when RPM's were turned up to 14.3VDC, so the stator seems to be charging ok. Verified coil, grounds, battery connections and etc. Took it for a ride yesterday, all good. Then after about 15miles it died at a red light. I got it fired back up, rode into a parking lot and it died again? Turned off the ignition, to reset everything. Then it started back up ok, ran the rest of the night? So my friend thinks I might have a bad ignition module? It does not seem like a fuel problem, because it just dies when it happens, I would think it would studder a bit if the Dog was not getting gas. Any thoughts much appreciated....

Sean
 

woodbutcher

Mr. Old Fart member #145
Staff member
:hi: try pulling the petcock and cleaning the screen. may have enough trash in it to clog up the flow. also, a cheap fix if that is the problem. don't forget the teflon tape when you put it back in.:2thumbs:
 

lee

Well-Known Member
could be your gas cap isn't venting properly - this causes a vacuum and stops the fuel getting through
 

mrbrown

Member
EHC

same deal with my 04 chop.
took to myrtle and just got embarrassed.:(
kept cutting off for no reason.
ck voltage to coil when it wont fire
you will see only bout 8 volts,, need 12 +
this is an output from EHC. to coil and ignition mod.
remember to reference the battery ground
long story short ya need a EHC. (or rewire)
my local dealer said 600$ plus.. in stock.:eek:
PM if you need wiring diagram.
 

ohio dog

Active Member
My guess is your 12 volt out of the ehc is bad. run a jumper from battery to red wire coming off ignition module three pin harness the next time it happens. I keep a small piece under my seat with some etape for this reason. Better than spending the $$$$$ right now....I know how you feel, happened to me a couple times at bike week too.
 

roedog

Member
Throttle Jockey,

I only use enricher when I first fire the the bike up for the day. Then close it after it is started.

Thks, Roedog
 

roedog

Member
Lee,

How does one know if there is a vacuum lock from gas caps? I removed them them when it happened thinking it might be a vapor lock, but it would only crank and not run still after doing this. I'm gonna take it out on Friday to see if it happens again, wish me luck.

Roedog
 

roedog

Member
EHC JUMPER WIRE

My guess is your 12 volt out of the ehc is bad. run a jumper from battery to red wire coming off ignition module three pin harness the next time it happens. I keep a small piece under my seat with some etape for this reason. Better than spending the $$$$$ right now....I know how you feel, happened to me a couple times at bike week too.
So you splice a wire into the red wire on the ign. module under the seat then to positive side on battery, is this correct? Do you keep it wired up this way after it runs? I had no errors on the LED lights when it happened?

Thks,
Roedog
 

roedog

Member
:hi: try pulling the petcock and cleaning the screen. may have enough trash in it to clog up the flow. also, a cheap fix if that is the problem. don't forget the teflon tape when you put it back in.:2thumbs:
Thanks, I was gonna do this when the tank was lower in gas. I looked in the tank with a flashlight and it didn't seem like there was enough shit in there to keep it from flowing. Ya your right it is a something I need to eliminate, just in case.


Roedog
 

lee

Well-Known Member
Lee,

How does one know if there is a vacuum lock from gas caps? I removed them them when it happened thinking it might be a vapor lock, but it would only crank and not run still after doing this. I'm gonna take it out on Friday to see if it happens again, wish me luck.

Roedog
if this was the problem you hear the air rush out when you unscrew the cap - this does not appear to be your problem.
 

lee

Well-Known Member
if its only cutting out when it gets hot it could be your cam position sensor - I think there have been issues with these before
 

woodbutcher

Mr. Old Fart member #145
Staff member
if this was the problem you hear the air rush out when you unscrew the cap - this does not appear to be your problem.
:hi: :hi: no disrespect, lee, but it would be the air rushing IN if it is vacuum locked. :2thumbs: :2thumbs: :2thumbs: :cheers:
 

ohio dog

Active Member
So you splice a wire into the red wire on the ign. module under the seat then to positive side on battery, is this correct? Do you keep it wired up this way after it runs? I had no errors on the LED lights when it happened?

Thks,
Roedog
Yep red wire in three pin harness coming from ignition module to positive side of battery. Yes leave it hooked up, otherwise ignition will lose power. It's worked to get me down the road a couple times. Also check the harness that runs from the ignition cam sensor that runs along frame. Make sure that it is okay. A bad connection there can cause goofy ass problems too.
 

roedog

Member
Yep red wire in three pin harness coming from ignition module to positive side of battery. Yes leave it hooked up, otherwise ignition will lose power. It's worked to get me down the road a couple times. Also check the harness that runs from the ignition cam sensor that runs along frame. Make sure that it is okay. A bad connection there can cause goofy ass problems too.
Ohio Dog,
Ok, i have 2-plugs coming off my ing. module (square silver with red LED, has Thunder heart stamped on it mounted on the back fender under seat) and both have a red wire in them? Which red wire/plug do you jumper? Your bike is currently wired this way? My bike starts up fine right now, so I'm gonna take it for a spin to see if it dies after riding a bit. What do new battery voltages read? I noticed mine will go down to 12.8vdc if I don't keep it on a tender. But the tender will keep it at 13.3vdc once it's hooked up. I just clicked the run button about 5x, to verify the ing. module on the battery was seeing a yellow LED (of the solid state ing. module strapped to the battery) when the headlamp goes out when starting. After doing these bump cranks the battery dropped down to 12.8 from 13.3, seems kinda fast to me? But the battery stays charging when the bike is running. The cam sensor is on the front right side of the bike correct, under the Baker 2 allen screw cap? I checked this sensor, seemed ok? Is there any other ing. modules on these bikes?

Thanks,
Roedog
 

Gas Man

Cool isn't cheap
Calendar Participant
Yep red wire in three pin harness coming from ignition module to positive side of battery. Yes leave it hooked up, otherwise ignition will lose power. It's worked to get me down the road a couple times. Also check the harness that runs from the ignition cam sensor that runs along frame. Make sure that it is okay. A bad connection there can cause goofy ass problems too.
He's on a 2003 dog... no crank sensor!

On the front of the motor between the oil filter and primary.

This is a crank sensor


This is what you should have or similar which is a block off plate for where it would be



Roe... what you have is a ignition in the cam cover. Its not the same as mine but its close. The cam sensor is just a pick up cup. It could come loose. There is a simple bolt into the end of the cam and keyhole on the cam that matches up with the pickup cup.

Here's a cam cover...


The pickup cup in its package on the right


Behind the pickup cup you can see the cam and the bolt hole and keyhole that the cup sits in



Your ignition module will look something similar behind the pts cover



Now understand if you remove the ignition you will loose your timing. You would then have to reset your static timing. Not hard just understand it.

Have you checked your coil first? Make sure you have power at its pickups.

Then maybe it could be the ignition and that would make it a good time to dump the thunderheart junk.
 

roedog

Member
Ignition Sensor Questions

He's on a 2003 dog... no crank sensor!

On the front of the motor between the oil filter and primary.

This is a crank sensor


This is what you should have or similar which is a block off plate for where it would be



Roe... what you have is a ignition in the cam cover. Its not the same as mine but its close. The cam sensor is just a pick up cup. It could come loose. There is a simple bolt into the end of the cam and keyhole on the cam that matches up with the pickup cup.

Here's a cam cover...


The pickup cup in its package on the right


Behind the pickup cup you can see the cam and the bolt hole and keyhole that the cup sits in



Your ignition module will look something similar behind the pts cover



Now understand if you remove the ignition you will loose your timing. You would then have to reset your static timing. Not hard just understand it.

Have you checked your coil first? Make sure you have power at its pickups.

Then maybe it could be the ignition and that would make it a good time to dump the thunderheart junk.
Gasman,

Allright I got the main man's attention, thanks Gasman. Yep your right I only have the pick up sensor and cup on the cam on the right side. I did remove it, to inspect but nothing loose or looked bad. Except a little wear on the inside of the sensor fork. I placed it back to the original location by matching the stand-off slotted screw marks. So it didn't seem to throw the timing off, I hope (it sounded ok when I started it today). Doesn't the Thunderheart ign. module red LED under the seat monitor the crank sensor if it is working properly? Cause it seems to work ok, lights up when run button is clicked on and stays on when the bike is running. I don't have the funky looking sensors (with dip switches) on the cam, is this on newer model bikes, or when you change out the whole Thunderheart system? This what my friend thinks was bad, but after I only saw the sensor for the pick-up cup I was confused as to what the ing. module he was talking about. Can the coil just loose power when the bike is running for awhile? I had spark when it crapped out that day. Where do check for power on the coil at the top and bottm (little guage wires) of the coil? I was missing a screw on the coil metal insulator strap thingy, but replaced it. But the bike still died after riding it the other day after about 15miles. I'm gonna ride tomorrow to see if it happens again. :bang:
 
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