weired spark, settings issue?

[chenz]

Hey fellow T-Brickers,

I have ms2 as the brain for my boosted 242. It has 2.8 code and I'm controling my tach input using a hall sensor.

I set the trigger offset to 10* and then turned the dizzy to get my 10* idle advance. The spark seems to occasionally jump to 7 then 4, 0 and back to 10 for a this seems to repeat itself every few seconds. the timing light says 10* (bouncing about a bit ro the 7,4,0)
But as the rpm increases from idle the spark retards to 0 then slowly climbs up after about 1500rpm with no more iratikness, though it does not follow my spark map.
NOTE: THE TIMING GAUGE IN MEGATUNE COPIES THE TIMING LIGHT.

If I adjust in trigger offset to 0* The light will read 15* advance and the engine sounds much happier and the advance gauge will slowly rise from 0* as the rpm increases. though this is nothing to what my spark map says. And retarding at the dizzy to 0 makes the engine sound steadily worse.
If I adjust the trigger wizard I get about 2*of change in the wizard before the engine stalls and it sounds happiest at about -27 trigger offset.
But then the Timing gauge isn't the same as my map or light

Im not sure how to upload my MSQ so here is my base ignition settings (megatune 2.8)
Trigger offset 10
skip pusles 3
predictor algorithm last interval

time mask 0
percentage mask 50
cranking 50
afterstart 70
normal running 25
Always check
falling edge
calculated
standard coil
going high

I tried the rising edge input capture. The car ran although was not so tolerant to large changes in the trigger wizard. Is rising edge the right edge for our red block mounted dizzys?

Apologies if it doesn't make much sense, I'm on a steep learning curve so any help would be appreciated. and Ill update tomorrow with progress.

Thanks

[chenz]

Problem solved. It was my knock retard kicking in. I don't know why as yet but disabling knock, now has the timing behaving.

Megasquirt is being a tough teacher :nod:

For future reference, can someone tell me how to post my MSQ's?

[740ATL]

You're right on there, it's a tough teacher, but I'll tell ya, it's the best way to learn. A year from now, you'l laugh at any problems or difficulties you once had.

You can post msq's by making a zip file out of them, then clicking on "go advanced", then "manage attachments." By going the zip route, you can post a much larger file.

Mike