MS3X and two-tower coils.. General Setup

[dcg9381]

I've got a Toyota 2RZ (2.4L) that runs 2 factory 2-tower coils.
It has VR outputs for the crank (36-2) and cam. I'm largely doing my megasquirt planning, lots of reading of the old manual... And I'm trying to decide how to do this.
My firing order is 1-3-4-2. The Toyota coils are "logic level" - that is, they have an ignitor built in that is triggered via 5v. They're similar to the LS-series coils, other than they are two-tower:


Someone help me understand how these are wired to MS3x and their association with plug position.

The nearest thing I can find is in the manual (http://msextra.com/doc/pdf/MS3XV357_Hardware-1.3.pdf) page 173, where it talks about wiring a quad-spark coil driver via two outputs A (pin 14) and B (pin 33). Here's the link: http://www.2rzturbo.net/wp-content/uplo ... g_ms3x.jpg

What coil goes on output A (pin 14)? What coil on output B (pin 33)?
How does MS know when to fire?

[grom_e30]

if they are logic level you can fire them from the ms3x card without the quad spark coils 1+4 will go to spark A and 2&3 to spark b, the outgputs are always fired in order eg a,b,c,d.. in your case for an engine cycle 720 crank deg would be a,b,a,b you would need to set it to 'wasted spark'

[dcg9381]

Thank you. Any references to docs where I can read more about this setup?

[grom_e30]

the pick you posted was close if you just omit the quad spark and wire the ms3x out put A (pin 14) directly to the coil for 1+4 and ms3x spark B (pin 33) directly to the other coil 3&2, they can share a common 12v, and also common power ground to the head, and i would guess the last pin is a logic ground again pair those together and ground that one to the main board connector on the ms3.

[dcg9381]

Thanks. I have them setup to share a common +12v. They ground from the factory at their mount (on the head). One wire (per coil) isn't used - it's some sort of Toyota diagnostic wire. The unused pins, I'm not planning on grounding...

Here's how I have them labelled currently:
http://www.2rzturbo.net/wp-content/uplo ... 24x532.jpg

[grom_e30]

yeah if that's the case leave the 4th wire disconnected.