[Kramer]

No Start - No Spark - Electrical Issue RESOLVED

I am not getting spark to fire up the bike.
Last ride was perfect, came home rolled it into the garage, all was well.

Next time out bike does not start. At all. Got a few small backfires early, then went chasing a fuel related issue. Only to find out that I'm not getting any fire to the plugs. I checked the main fuses block and those are all good.

Currently I'm not getting any backfiring, just cranking. Fuses and battery are good. I hear the fuel pump, as normal. Lights and gauges work. I hadn't done any work on the bike just prior to the trouble.

Any other suggestions? Thanks.
Of course, I'm trying to take a 4-day ride next week. This just HAD to happen. Oh well. At least it didn't happen on the road.

 

[jcns]

check your relays.

 

[Kramer]

Thanks. I just swapped the ones under the seat. But I'm not what those are for. there appear to be three under the headlight fairing. What do those do?
Again, all lights, signals, horn work. I hear the fuel pump, etc...

Thanks for the input.

 

[dr1445]

did you check for spark at both the spark plugs?

 

[volleykinginnc]

I believe that the two under the seat are the fuel pump and the fan relay. I don't have any good words of wisdom for you but it sounds like you are having the exact same issue I am. I will wait for more responses before I take out my fuel system.

 

[Kramer]

No spark @ either plug.
All other electrics look to be okay.
I swapped around all of the similar relay's. Or at least the 4 similar ones. there appears to be a 5th up front. Disconnected it to see if I could fid what it was for. But I cannot seem to see what it does. No differences connected/disconnected.
Still at a loss.
Where is the crankshaft position sensor located?

 

[RedST]

You would have to take off the fairing for this, but also check the leads going to the coils. The coils are on brackets under the side panels (each side) near the upper front.

 

[Snyca]

Had the same issue. Crankshaft sensor was to far end of tolerance. Nichols repair shop did adjustment as well as reset the ecu due to error codes. All is fine. They will help you over the phone if you are stuck. They are incredibly helpful.

 

[Kramer]

At this point, I'm thinking C P S as well. Not sure what I can do about that. I'l be calling the shop in the AM.

 

[Kramer]

You would have to take off the fairing for this, but also check the leads going to the coils. The coils are on brackets under the side panels (each side) near the upper front.

For grins, I did take off the side panels and took a look @ each of the coils and associated wiring. But since neither plug is gettng fire, I can't believe it would be either of those.

 

[RedST]

For grins, I did take off the side panels and took a look @ each of the coils and associated wiring. But since neither plug is gettng fire, I can't believe it would be either of those.

I have been noticing a few people that have posted "my bike won't start" threads after riding and then washing them.

Whenever you have an older bike, washing can and does introduce water into electrical connectors that have aged and cracked, or lost insulating grease, causing corrosion.

Sounds like you got things under control with the CPS, but it never hurts just to trace out the electrical side of things to make sure you don't have a fault.

Good luck!

 

[Kramer]

Are you calling my bike OLD?! Do those pipes make me look fat?!

LOL

Can anyone tell me more about the Crankshaft Position Sensor and how to check it?

Scratch that. DANGIT! Looks like I have to pull a water hose to get the CPS out of there. Amazing! I'll be down to bare frame before long.

 

[PookaDog]

Sounds like you have the exact same problem as I have.
Connections at the battery are fine, fuses are good, fuel pump primes but no spark at the plug.
Mine cut out the instant I honked the horn. Just died. Happily, I was near home so I was able to push it.

Anyone have any idea if the horn alone could have caused this issue? I couldn't find any visible shorts last night.

The horn has been on the bike for two years and the bike hasn't been washed or left out in the rain recently.

 

[RedST]

Are you calling my bike OLD?! Do those pipes make me look fat?!

LOL

Seriously, I was recently told that my ST was more fat than a 1098 because of the pipes. This was in relation to getting it out of a van.

 

[Kramer]

Spark Issue Resolved

Thanks to Alain of Corse Motorsports in Nashville, TN. He talked me through fixing things up. I was going down the right road (in the end).

Apparently, a fairly common issue to "no spark" is the CPS (Crankshaft Position Sensor). It's just in front of the water pump and DOES come out (although I didn't think it would). It had just a little grime on it. Wiped it clean re-installed everything and she fired right up.

So bottom line: IT WAS THE CPS. But it wasn't bad. It was either the connection on the pigtail (although that looked good), or the small amount of grime (almost looked like a small bit of magnetic dust) on the end of the C P S.

Luckily I had time in between conference calls (on my lunch hour of course) to look a little deeper into this. It took a long time because I was checking and tweaking so many different things. But if I went right to this it would've been a piece of cake.

Thanks to everyone for the replies. I hope this will help others.

 

[PookaDog]

Hi Kramer - glad it worked out for you.

Could you tell me what the TPS looks like? I think that's my next thing to check. All my connections seem fine, but I haven't swapped out any relays yet.

Thanks.

 

[Stick]

TPS = Throttle Position Sensor
On the right side of the throttle mechanism, you have the throttle cable. On the left side of this shaft is the TPS "black box".

Kramer: Did you really remove this thing from the throttle shaft? It's a precision "volume control" that needs to be placed back EXACTLY where it was set.

FYI: It's measures the amount of twist that you have on your throttle. The Input is a precision 5V from the ECU. It's out put is a precise percentage of the 5V.
Like at idle, it may be 453mV (Milli Volts) or some such number, and you can just randomly "bolt it back on" (unless you can also walk on water, heal the blind, etc). Maybe Obama can do it? Prolly not!

Or is it keyed on the shaft? I never had one off...

 

[Kramer]

Guys,
I must've been too excited to type yesterday. i have since corrected my post.
It was the CRANKSHFT POSITION SENSOR (not the tps). It's on the left side of the motor (while sitting on the bike) just in front of the water pump. Follow an electircla lead to it. You must remove some tie wraps to loosen the wire enough so that t will come out. But it WILL come out without disconnecting any plumbing. It's kind-of behind a coolant hose, but it's more below it than it appears. There's one bolt holding it in with a shim/washer between it and the case.
toughest part is unbundling the wires to get to the connector.

 

[stryder]

Well, I was just about to post up about my starting problem that seemed to be based in a very similar no-spark conditon when I read this thread. It looks like cleaning the CPS will also work on ST3 models that seem to have no spark. I ended up removing the upper rad hose at the pump housing to better facilitate refitting the CPS after being able to remove it with the hose on. I hope it starts again tomorow.

Thanks for the thread/info Kramer.

 

[Kramer]

Hope the TPS cleaning works out. Keep us posted on your status.