MS2 upgrade to spark control

[Mike280zx]

Hi all, hoping for some clarification on a couple items regarding upgrading from fuel only to fuel & spark (apologies if they seem to be basic/simple questions)

 

Currently I am using MS2 V3.0 with NA Distributor and coil negative tach input. I have installed a turbo distributor with the DIY Optical Trigger Wheel and am following the instructions DIY has online:

https://www.diyautotune.com/support/technical-articles/install/nissan-datsun/megasquirt-your-280zx-turbo/

https://www.diyautotune.com/support/technical-articles/hardware/nissan-trigger-disc/

 

I am making all the necessary changes in the ECU as per the Trigger Wheel document (like cutting out some caps/resistors) as well will add the 1k resistor to S12 & TachSelect in the ECU versus under the hood or at the distributor harness pin 24 (I believe this would eliminate the need for the 1k resistor connecting 12v to the Pin 24 wire noted in the diagram)

 

Currently I have the shielded wire from Pin 24 going to the coil negative. With the upgrade Pin 24 wire should move to the distributor as the MS Trigger and pin 36 wire needs to be added as the ignition trigger to the coil negative. 

 

My questions..

- should the Pin 24 wire remain as the heavy shielded wire? ...spidey sense tells me the negative coil wire should be shielded not the one to the distributor. If not, what gauge wire is recommended for Pin 36 to coil negative?

- should the 12v feed to the distributor be on a separate fuse/circuit or can I tap off the coil positive for this (seems like that is the way the NA Distributor module gets its 12v feed).

-finally the last sentence in Optical Wheel "Wiring" section says "The primary trigger always wires to pin 24 on the main board DB37. For MS2, the second trigger wires to pin 3 on the main board DB37, or pin 7 on the DB15 if using the optional V3.57 DB15 input".....what the hell does this mean regarding pin3??? (that is a ground I believe)

 

Thanks in advance to anyone helping me with this upgrade.

 

 

 

 

[darom]

Hi @Mike280zx, if you don't get answers on this forum, i'd advise to post on https://www.msextra.com/forums/index.php 

 

Regards and good luck with your project.