Loss of spark / revs

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nakedninja900
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Re: Loss of spark / revs

Post by nakedninja900 »

Hi Guys
OK I've set up the timing light and I'm getting a good signal however the engine wont run ,it keeps throwing the spark advance into a negative number (-14deg) and then back to what I set (8deg) so it keeps kicking back, from what I can see when it sparks at 8deg its not far off but I cant understand whats telling it to advance so far.From what I can tell with the timing light it alternates between -14 and 8 every revolution.
Thanks
Matt Cramer
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Re: Loss of spark / revs

Post by Matt Cramer »

Could you capture this in a data log and post it along with your MSQ?
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nakedninja900
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Re: Loss of spark / revs

Post by nakedninja900 »

Matt
How do I upload a data log? its keeps trying to upload the complete magaviewer.
Thanks
nakedninja900
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Re: Loss of spark / revs

Post by nakedninja900 »

As soon as I start cranking it mirrors my trigger offset in degrees as you can see here
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I have the advance set at 4deg
Matt Cramer
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Re: Loss of spark / revs

Post by Matt Cramer »

Select the file that ends in MSL for the log and MSQ for the tune.
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nakedninja900
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Re: Loss of spark / revs

Post by nakedninja900 »

I have got the timing bang on now with the timing light, I ended up with 12,5 deg offset. I still had the problem with the timing swinging into a negative number while cranking so I lowered the cranking RPM to 300 and that seems to have cured it.
I'm booked in for a dyno run on Saturday so we'll see how she runs. I'm having no joy with the tachometer though, I'm running an aftermarket Koso unit but there's no info in the manual about the Tacho out wire, does this give a positive 12v pulse?
Matt I seem to be having a bout of stupidity but I still can't post the datalog even though I posted an msq on the previous page I can't remember how I did It!
Help I'm stoopid.
kholman
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Re: Loss of spark / revs

Post by kholman »

Attaching the file: When you click "post a reply" there are tabs below the preview/submit buttons, click on the tab "Upload Attachment" then select the file off your computer and "add the file".
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nakedninja900
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Re: Loss of spark / revs

Post by nakedninja900 »

?
Last edited by nakedninja900 on Wed Oct 24, 2012 1:56 am, edited 1 time in total.
nakedninja900
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Re: Loss of spark / revs

Post by nakedninja900 »

I hope this works.
The main problem is the ignition advance changing to a negative number when cranking , once started its fine but it really struggles to start. I have the dwell set at 2,5m/sec but it stays at 2,0m/sec.
Attachments
CurrentTune.msq
(30.04 KiB) Downloaded 158 times
Matt Cramer
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Re: Loss of spark / revs

Post by Matt Cramer »

Is your IAT sensor working correctly? It may be triggering the IAT based ignition retard if it's giving a false reading.

Have you tried changing the Cranking Trigger setup from Trigger Rise to Calculated?
Matt Cramer at DIY Autotune
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