Ignition timing confusion - Help!

[briz]

I'm having a hard time getting my project to start. Basic details:
Weslake 50 degree 1000cc v-twin set up for dual spark with 2 VR sensors set 50 degrees apart. 2 separate coils, no cam sensor; wasted spark.
Single tooth trigger wheel which triggers at 8 degrees BTDC.
I think I set everything up right in Tuner Studio; set to 'trigger rise' and trigger offset to -352 degrees.
My understanding was that with it set to 'trigger rise' it would basically fire at the triggering point whilst cranking.
Instead I'm getting a spark roughly 50 - 60 degrees retarded (its not easy operating a strobe whilst pressing the starter button!)
Any ideas? I've been trying to start this thing for 4 days and am getting close to sledge-hammering it!
Heres screenshots of ign setup:

[Bernard Fife]

Briz,

From your description, it sounds like your input capture edge may be mis-configured. When a VR sensor signal is sampled on the wrong edge, the trigger will be offset and somewhat variable.

'Ignition Set-Up/Base Ignition Settings/Ignition Input Capture', you might want to try the opposite edge (there are only two possibilities, so use the one you aren't currently using). In your case you have set 'Rising Edge' and you might need to set 'Falling Edge' instead.

There is much more on this here: http://www.megamanual.com//ms2/pickups.htm#vr

Lance.

[grippo]

Your understanding of trigger rise is correct. Your configuration also looks correct, but since this isn't a true toothed wheel setup, I think using 8 deg trig offset might be better. I don't know why the spark is 50 deg retarded, but, since the odd-fire angle is 50 deg, is it possible the sparks are going to the wrong cylinders ? Another possibility could be the wrong polarity on either the ignition output or the wheel vr input. For example if you were triggering on the leading edge but thought you were triggering on the trailing edge, and the tooth was about 50 deg wide, you might get something like that. But if the tooth is narrow, then that isn't likely. Another possibility if you are using code 3.7x: for your setup you need to unset autoTrigger in the ini file. This is a text file and you can find "set AUTO_TRIG" in the first few lines. Just change set to unset. You also have to unselect it in TS and cycle power. Ignore all this if you are using 2.905 or below code.

[Edit note: I submitted this just after Lance's post which didn't show up until after I hit the button- so there is some redundancy here.]

[briz]

Thanks guys.
The possibility of 'wrong cylinder' wiring was the first thing I looked at, but its wired correctly; both cylinders are retarded.
I followed the recommendations in the mega manual when making the trigger tooth and made it the same width as the sensor tip width - its only about 2mm wide at the tip so it can have little effect on the timing.
Not sure about which code its running; its a version 2 microsquirt, bought about a year ago.
I'll try the8 degree setting and the falling edge suggestions too.
I'll get a log of it cranking later on too.

[briz]

Hmmmm....
I have been having trouble with my strobe light, its not been responding well, which turned out to be low voltage on cranking.
Hooked it up to a remote battery and things look different.
The timing is hunting back & forth between 30-40 degrees retarded to about the same advanced. On both cylinders.
There is only the one tooth on the wheel. Gap is close; about .010". Tooth stands about .200" proud of the body of the wheel.
Could the sensors be picking anything up from that distance? If they could, why would the timing vary back & forth?
It should be added that this cranking was with plugs out and quite a bit faster than normal.

[briz]

Well, after a 2-week excursion into msextra code and getting nowhere, I loaded the most recent B&G code and with some tweaking, we have sparks occuring in the right place.
Still no-go though. Tried everything with the cranking fuel pulse, sometimes it kind of wants to start.
Now I've toasted the starter!
I guess this should continue under 'tuning fuel & air'.