To expand on things, if you are capturing the wrong edge of the tooth (rising/falling) timing will change with RPM. When you have it correct, timing will stay at whatever you have it set to.
This is why it is critical to use a timing light and verify that not only do you have your trigger offset set up correctly when in fixed timing mode, but also rev the engine to verify that timing does not change.

I went for years with timing fixed at 22 degrees. It isn't ideal for drivability with a high overlap engine BUT it will at least work and leave you with one fewer thing to think about while you sort other issues.

*Thread revival*

Figured i'd get back to trying things..

So I tried switching Rising/Falling Edge capture as suggested. No good. Ran a composite log on rising edge: steady signals, no sync loss. Ran a composite log on falling edge; steady signal, lots of lost syncs. Ran a tooth log on rising edge: steady signal. Ran a tooth log on falling edge: no signal at all.

Any idea's are very welcome and appreciated

Two things, with my car, I ended up taking the MS3 out of its case, and running the car where I had access to its guts, to adjust the two pots for the VR sensors, because at idle, it was clear, but broke up over 3000 rpm, the unscrew it all the way that the guide was too much for mine.

Second thing, way back in post 13 you mentioned that you locked to 5 degrees. I belive it was supposed to be -5 degrees, not positive 5, so you might have yours off a total of 10 degrees

Pro boxes have much better circuitry than the B&G kit board based units, they have no adjuster pots. In my experience with them they just work with any sensor.

As Peejay confirmed; the Pro boxes are a different breed, comparable to off-the-shelf Haltech/AEM. There's no pots to adjust.

It was locked to -5° advance/btdc, a weird way of saying 5° retard/atdc. Checked it all again today, from stabbing le cas to confirming base timing etc. It all checks checks out.

I did however find another curious thing; T1 plug keeps fouling / getting and staying wet. See one of my earlier posts with a video confirming all 4 plugs have spark. So idk what's going on now.

Any ideas?

The wet plug thing keeps bugging me.. Could it be blow-out due to a weak spark? I'm runnig IGN1A's from AEM but don't find the sparks looks awfully bright when I look at them. I'll go over the coil wiring, input voltage and grounds again tonight. If it sees 12v in and the grounds check out, what could be causing a weak spark on them?

Still tho that leaves me guessing as to why only the front trailing stays wet..

IGN1As can use quite a bit of current, like 15A each with a lot of dwell. If your wiring is too small they might be choking for current?
Basically only that or also not enough dwell could cause weak spark, but tbh IGN1As don't need all that much dwell, a couple ms should be enough, i think people usually use like 3-4ms on those.

I know how frustrating ignition can be, it took me 2 years to figure out my ign problems on microsquirt. In my case the outputs were(are) designated incorrectly in the hardware manual for FC mode.

I looked into whether the Test Mode vs Spark Output designations could be different for you on MS3 Pro, but they appear to be the same. On Microsquirt it's really confusing because Spark Out A,B,C,D correspond to Test Mode Coil A,C,D,B.

If you pull the boot off T1 while it's running does it change at all? You've tried new plugs? Swapping coils around? I know when I was having timing issues and I ended up with wet plugs, they wouldn't fire at ALL. It sounds like you're almost at the point where I was, having to put a scope on all the friggin' spark outputs.

Plugs are new. Haven't swapped coils around yet. Coils get their juice over a 16 gauge wire. Haven't pulled trailing wires yet while running. Also haven't swapped plug wires yet. It currently idles at 15° BTDC, wanna try lowering that and see what happens. Read about a guy with similar misfires fixing it by lowering idle timing to 0° L.

From what I gather these ms pro ecu's aren't the most reliable units made. I've seen a few posts where the unit was faulty with ignition issues. You might want to contact DIY autotune with the issue.

Thanks for replying. I've been hesitant to contact DIY because 9 times out of 10 it's the build/tune screwing something up and I don't wanna doubt their product without knowing my side is sound. But yes, I've been at this for so long the time might have come. I've sent them an email.