motorbike ignition fault

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Re: motorbike ignition fault

Postby Robski » Sun Sep 30, 2012 11:10 am

Fat Freddy wrote:To me, it kind of looks like it's tracking to ground.

What colour are your plugs?


FF



1&4 does but what about 2&3 ?
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Re: motorbike ignition fault

Postby Fat Freddy » Sun Sep 30, 2012 11:34 am

I think the same.

First kick on the Primary and nothing on the secondary.

FF
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Re: motorbike ignition fault

Postby tiggerbiker » Sun Sep 30, 2012 11:52 am

here are the latest traces i have obtained - hope they are useful,
robski, your picture was very helpful - thanks
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Re: motorbike ignition fault

Postby tiggerbiker » Sun Sep 30, 2012 11:54 am

oops - heres the traces
Attachments
bandit12 coil 2+3.psdata
(192.35 KiB) Downloaded 194 times
bandit12 coil 1+4.psdata
(202.87 KiB) Downloaded 193 times
ign. pickup + pri. amps.psdata
(1.88 MiB) Downloaded 200 times
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Re: motorbike ignition fault

Postby Robski » Sun Sep 30, 2012 1:30 pm

Fat Freddy wrote:I think the same.

First kick on the Primary and nothing on the secondary.

FF


Is it not correct that everything after the EMF kick (spark line) in the primary is a feedback of the secondary ? so why don't they match then if the secondary is shorting to ground(picture in previous post) (picture below of 1&4 which i agree looks like short to ground) ?
Bandit.JPG


OP can you verify if you were coupled to the correct side of the coil secondary (+/-) as you don't seem to have changed probes & there is a strange sub zero voltage going on ?
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Re: motorbike ignition fault

Postby tiggerbiker » Sun Sep 30, 2012 1:36 pm

Robski wrote:
Fat Freddy wrote:I think the same.

First kick on the Primary and nothing on the secondary.

FF


Is it not correct that everything after the EMF kick (spark line) in the primary is a feedback of the secondary ? so why don't they match then if the secondary is shorting to ground(picture in previous post) (picture below of 1&4 which i agree looks like short to ground) ?
Bandit.JPG


OP can you verify if you were coupled to the correct side of the coil secondary (+/-) as you don't seem to have changed probes & there is a strange sub zero voltage going on ?

hi, yes i have connected to the correct feed.
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Re: motorbike ignition fault

Postby Robski » Sun Sep 30, 2012 8:29 pm

tb

Can you give us a heads up on how this ignition system works, how many wires to a coil pack, is there an ignition module etc ?

The last captures you have posted including the coil current have some crazy dwells going on & current amplitude, were both captured under the same conditions ?
The current ramps also look like there's a short with steep start to the up ramp & negative switch off characteristics & one is almost a square wave.

Where does the ignition pick up come from ?

Have you checked the resistance of the plug leads ?

Do you have an adjustable spark tester ?

PS pay attention to your sample rate, detail can be lost if zooming in when the sample interval is low.
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Re: motorbike ignition fault

Postby tiggerbiker » Sun Sep 30, 2012 8:41 pm

Robski wrote:tb

Can you give us a heads up on how this ignition system works, how many wires to a coil pack, is there an ignition module etc ?

The last captures you have posted including the coil current have some crazy dwells going on & current amplitude, were both captured under the same conditions ?
The current ramps also look like there's a short with steep start to the up ramp & negative switch off characteristics.

Where does the ignition pick up come from ?

Have you checked the resistance of the plug leads ?

Do you have an adjustable spark tester ?

PS pay attention to your sample rate, detail can be lost if zooming in when the sample interval is low.


hi,
there is an ignition pickup on the end of the crankshaft which feeds to an ignitor module / ecu which then feeds 2 coil packs, each with a common positive feed and having an individual negative trigger.
the captures were taken within 1-2 mins of each other ( one of them i had the clamp facing the wrong way :oops: )
i do have a sparktester but its MIA at the moment - our tool van comes on wednesday so will buy another (no doubt i will find my old one on thursday!)
whats the best settings for running these kind of tests? - i have been using the built in automotive menu to do the setting up for me
thanks for your help and advice - its very much appreciated

ohh, found a wiring diagram online here: http://www.customfighters.com/forums/sh ... hp?t=46444
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Re: motorbike ignition fault

Postby Robski » Sun Sep 30, 2012 9:25 pm

Is the ignition pick up supposed to be a square wave ?

Check the power supply to the coils matches batt V( guessing they should be?) when cranking, check the supplies & grounds to the ignitor module.

Get your spark tester or a plug in the lead end & you be the ignitor module & ground the coil switched side with a test light from batt- quickly & release, the other side must be powered ie ign on or power probed, is the spark stronger ? (don't forget to ground the spark plug)

When I scope for ignition I set a sample rate for a 1µs sample interval.
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Re: motorbike ignition fault

Postby Fat Freddy » Mon Oct 01, 2012 12:29 pm

Robski wrote:
Fat Freddy wrote:I think the same.

First kick on the Primary and nothing on the secondary.

FF


Is it not correct that everything after the EMF kick (spark line) in the primary is a feedback of the secondary ? so why don't they match then if the secondary is shorting to ground(picture in previous post) (picture below of 1&4 which i agree looks like short to ground) ?
quote]

In theory, Yes.
But your second question disproves the first. For example if I grounded a plug lead would you expect to measure no induced voltage in the primary.

TBH I think this has more than one issue and I agree the dwell does not look right. Two long, two short - hows that fit with cylinder comps? Amp clamp?

FF
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