MicroSquirt.com read only forum (Jan.15,2018)

I can't get past this point and its getting frustrating, I know i'll get it but need some help from the "Dual spark twin cylinder guys" here is what I have:

-Kawasaki 90deg Vtwin, firing order, front cylinder then rear cylinder, I beleive rear cylinder fires 270 degrees after front cylinder.
-Using LS1 coils off early silverado 5.3 GM# 12558693, The "ABCD" letters are on the plug, but the plug matches the LS2 diagram posted on this forum, Either way both diagrams wire ABCD the same so thats what I did. "A" is gnd, "D" is +12v etc.
-trigger is VR with 24-2 wheel, tach signal is steady while cranking at 130 rpm, a little slow but it is solid.
-the VR sensor is at 12:00 (TDC for front cylinder) and the missing teeth are in between 4 and 5 oclock, rotation is counter clockwise, delay teeth is 13.
-Using dual spark mode, with the output #2 set to fire at -270, msq is below. This is what I am not sure of.
-removed plugs from cylinders and grounded them so i could watch them.
-when i turn ignition on both plugs will spark about 0.5 seconds after uS boots, I don't think its supposed to do that, it may be the rising/trailing edge spark setting.
-when cranking I mainly only get one plug to spark. I can jack around with offset for output #2 and then I can get the front one to fire and no rear one. Its inconsistant, if I leave the system off for a while and start it up and start cranking, i will get spark on both and then one dies after 3 or 4 sparks and the other cylinder will keep sparking.

Can someone look at this MSQ and see if there is a setting problem.

tech3sandcars wrote: -when i turn ignition on both plugs will spark about 0.5 seconds after uS boots, I don't think its supposed to do that, it may be the rising/trailing edge spark setting.

Sorry can't help with the V twin settings as don't have one, but the above quoted behaviour is normal. When I had 12V LEDs attached to my injection and ignition outputs on the bench, they used to flash once on start up, that's switching the Microsquirt on but before cranking.

It was a useful way of knowing all was OK for me.

Have you tried using a 90 degree offset instead? Normally the second cylinder would fire 180 after the first, but being odd fire it's offset by another 90.

Here is a diagram as well, right now I have have both plugs out of the cylinder and grounded to the frame, just trying to get both of them to fire consistantly, when I put them back in the engine i'll worry about the output #2 and whether it is misfiring or not. I origionally thought about 90deg but the manual says the number is always negative and you need to think backwards ( it actually fires 270 deg before cylinder one)

Here is the diagram:

Just read another post "Odd fire problem" seems his problems were corrected using "calculated" for cranking trigger for his 90deg vtwin....any thoughts? is that a must? documentation seems to not explain that parameter very well.

I ran the tachref.exe program and have included a jpg shot of the results. it looks good to me but anyone else????

OK progress, I think. I moved to the new 3.43 beta code and its got some new settings in respect to Dual Spark setups. I now get both plugs to spark one after the other (it looks like 90deg apart) and in the proper order, no idea yet if the spark times properly with the cylinders. The new code looks like it wants a positive number not a negative number that the old documentation stated for the offset, they now call it "Offset (advance) for cylinder #2 (degrees)". A negative number would only fire one plug. There is also a setting for whether you are firing 2 coils tied together , or separate coils. Not sure if it was this code variant that helped or the way the added a couple options that made it less confusing. I will report back if this fires off properly after the weekend.

In addition to the code there was some more additions to the documentation. See - http://www.megamanual.com/seq/multichannel.htm. This has examples and procedures at the end, including for odd-fire.

Hey thanks, was there that much code difference in 3.430 or is it just layed out easier in the configuration? Hey Grippo did you look at my tachref diagram above? Does it look proper?

I don't think there is any difference in the code for your configuration, most of the changes were for the sequencer. But I think the ini file is better laid out for dual spark stuff.

Yes I looked at your diagram and if you measure the distances between falling edges (that is all the ecu sees is time differences between falling edges) you will see that you get a sequence like t,t,3t,t,t where t is the distance between regular teeth. This is what you should see for an N-2 wheel. You can do it by marking off the edges onto a piece of paper. But there is some variation because the engine has to compress air and then it expands.