05 ST Ignition Problem - No Spark

Art Franz

Art Franz

Joined
Jan 6, 2010
Messages
332
Location
Lacombe, AB Canada
Bike
05 ST1300
Hi everyone,

I did some maintenance work during the last few weeks, during which I removed the throttle body to tighten clamps, checked thermostat, and removed all of the front sub-frame assembly to clean up some wiring, and install some more wiring. I put the dash back on, and thought before I go too much further, I'll check and see if everything's working. Well, it's not - won't start, no spark.

I went back, and removed everything that I had taken off and put back on, and checked all the connections, and re-checked them, and that all appears good. My battery is good - it's cranking as normal, and I have my charger hooked up and charging to replace the power that I use while testing.

So now I'm in the Service Manual, page 20-4, Ignition System Troubleshooting. No spark at all plugs-that's me.

In the first diagnostic check called Ignition Coil Primary Voltage, I just want to make sure I'm understanding this correctly - I take it that the "initial voltage" under the Unusual Condition heading means 12V at the coil feed? - if so, yes, I do have 12V at the coil. When I'm cranking, approx 9V at the coil, which I believe to be correct. So that's not my "unusual condition".

In the second 'Unusual Condition" it says "peak voltage is normal." I take it that 'peak voltage' means the voltage that comes out the spark plug wire - is that correct? So that's not my 'Unusual Condition' either. Because I have no spark. Am I still correct here?

3rd Unusual Condition - THIS ONE'S ME - Initial Voltage is normal - yes, I do have 12V at the supply wire at the coil. And I have no peak voltage (no spark) while cranking the engine. So under the Probable Cause heading, #1 & 2 are about testing the equipment that I should have ACCORDING TO THE MANUAL, but I don't have this equipment. But I also have no spark, so that means my 'peak voltage' is incorrect, doesn't it? By process of elimination, then, does this mean that my 'Probable Cause' is #3? A faulty ECM? PLEASE SAY IT ISN'T SO
 
Art I think 9volts cranking is getting low, some ECU's don't like that.
Why not try jumping it, cant hurt. IMHO.
Bob
 
12v at the coil primaries but no spark would normally be bad coils or wires, but it seems too unlikely that both coils or all four spark plug wires would fail simultaneously. Did you disassemble the spark plug leads from the coils at some point?
 
Hi Gary, how's it goin? Been cruising those awsum canyons? That was definitely a hilite when I was there; a bigger hilite was meeting you and your family and getting your help.

Did you mean that 65 amp bar fuse? Yup, it's good. All the lites are on, on the dash. Everything seems to be working, except the spark plugs. I've been working on this problem for a long time now, probably off and on, 12 hours. It's gotta be something I've overlooked, or done wrong, but I just can't find it.
roadriderg said:
Did you check the main ecm fuse on top of the battery. The engine will still crank even if this fuse is blown. But ecm lights on the dash will be out...
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Yes, I hooked it back up. In fact I tested it by probing the wires after the connector, and it tested good. Thanks for the tip, tho. A

At first, I was getting a code 9 which is Intake Air Temp. Because I had the airbox off. I hooked it back up, the code's off. Just a minute --

5 min's later -- I went and checked the FI lite turn the key on and a really quick flash, maybe 1/4 second, and then off. Earlier today, it was showing normally, as you said here, and then the code 9. Now, there's no code 9, and the IAT is unplugged. ???

The most recent thing I've done, is I've got a wrecked 06 in my shed, and I robbed the ECM off it. Swapped it out. No change. Put the 05 ECM back on.
sennister said:
Did you hook it back up? That has caught more than one member around here.

Is the FI light functioning normally? On with ignition for a few seconds and then off?
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Cycle your kill switch a few times. I have seen stranger things happen. You shouldn't get any FI light if it is the kill switch but hey. Quick thing to test.
 
I did not disassemble the plug leads from the coils, any of them. I've got 12V to the coils, but somehow the bike isn't telling the coils when to fire. There isn't a pulse coming down the other wire (that I know of, I don't know how to test that) to trigger the coil to fire. And I don't know how to check the various components that cause that pulse to come down to the coil.
wjbertrand said:
12v at the coil primaries but no spark would normally be bad coils or wires, but it seems too unlikely that both coils or all four spark plug wires would fail simultaneously. Did you disassemble the spark plug leads from the coils at some point?
Click to expand...
 
Where is the crankshaft position sensor? I haven't looked for it but maybe you disconnected that by accident. I would assume it is on the side of the engine somewhere. That wouldn't explain the quick flash of the FI Light. I know if the kill switch is tripped you won't get a FI light on ignition on. It also should kill ignition so it is a good thing to verify.
 
sennister said:
Cycle your kill switch a few times. I have seen stranger things happen. You shouldn't get any FI light if it is the kill switch but hey. Quick thing to test.
Click to expand...
I just went out and did that (for about the ump-teenth time lol). While I was there, I took some of the fuses out and re-checked them. After I re-reinstalled the throttle body, I forgot to connect the plug that goes to the (I think it's called) evap-cannister. Just now, I discovered that as well and re-connected it. Now, I get: the FI lite comes on, the fuel pump does it's hum thing, as the fuel stops it's hum, the FI lite blinks off real quick and back on, and then it stays on.

It's gotta be something real simple somewhere, but I must be too simple to be able to find it. Someone on here will remind me of something and then I'll hit my head real hard with the palm of my hand (hopefully I don't have something big and heavy in my hand at the time) and make a real loud DOH. And then it'll all be good. But till then - -
 
sennister said:
Where is the crankshaft position sensor? I haven't looked for it but maybe you disconnected that by accident. I would assume it is on the side of the engine somewhere. That wouldn't explain the quick flash of the FI Light. I know if the kill switch is tripped you won't get a FI light on ignition on. It also should kill ignition so it is a good thing to verify.
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There's a Cam Pulse Generator under the throttle body whose wires are part of the throttle body harness that I had off. I wondered about that, and took the throttle body off again after my initial post here. It was good. No changes. But I'm getting good at taking that throttle body off (and on).

Then there's an Ignition Pulse Generator on the front of the engine, left side just below the rad. It took it off (again) and it and the connections appeared good. Haven't found how to test it yet, though. I think I'll try that next.

Thanks again, some great ideas here.
 
I think the crankshaft position sensor is called the Ignition Pulse Generator. It looks like it is on the front of the engine. It appears to be next to the covers for the timing marks.
 
Art Franz said:
There's a Cam Pulse Generator under the throttle body whose wires are part of the throttle body harness that I had off. I wondered about that, and took the throttle body off again after my initial post here. It was good. No changes. But I'm getting good at taking that throttle body off (and on).

Then there's an Ignition Pulse Generator on the front of the engine, left side just below the rad. It took it off (again) and it and the connections appeared good. Haven't found how to test it yet, though. I think I'll try that next.

Thanks again, some great ideas here.
Click to expand...

Heh, beat me to it. The cam pulse generator was my next guess.
 
IPG has two wires. My guess is that it will either show closed or open and as the engine turns over it will toggle the output at certain points in time when it should trigger the signal to fire a spark.

You might be able to pick up on it with an ohm meter. It is possible that it will toggle too quick to see though. You could pull the spark plugs and turn the engine by hand like you do when you do the valve check.

There is some info on it on 20-7 of the SM.
 
Continuing down the chain of things that can kill the engine. What about neutral safety switch. Next to the oil sight glass between the headers. Long shot on that one. What about sidestand switch. I have seen them break where they think the sidestand is down even though it isn't if you are in N it shouldn't matter.
 
sennister said:
Continuing down the chain of things that can kill the engine. What about neutral safety switch. Next to the oil sight glass between the headers. Long shot on that one. What about sidestand switch. I have seen them break where they think the sidestand is down even though it isn't if you are in N it shouldn't matter.
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Thanks alot for your help, sennister. I've been working on this thing for about 10 hrs today, and I've had enough. My next step, should be able to get to it some time tomorrow, will be the IPG.

An advantage I've got, is a wrecked 06 (running) that I can rob and swap parts from. As I mentioned above, I've already tried the ECM, and I'll try other parts until I can find the problem.

I'm still not convinced that it's a part that's failed because this all came about after I took this thing all apart. Coincidences just don't cut it with me. Unless I mistakenly shorted or fried something out. There's gotta be a wire pinched, a connector not right, something not hooked up, and it's a matter of finding it.
 
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