I've got a 90 Miata, (MS Labs MS3) that I've just completed a very plug and play LS Coil installation on using the Flow Force coil kit.

The car started up right away andrand great, but I've got no tach movement on the dash.

​​​Per the instructions on given by flow force, I tried connecting yellow/blue (tach output) to black white(ignition output to ECU). This didn't work. Igniter is now unplugged as I understand it's it's completely out of the picture now.
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After doing some Investigating and consulting the MsLabs wiring guide, I realized I have no tach output wire on pin 10 of the db37 connector. I made the change to the blue, fidle wire on pin 37 since it's an available output wire, routed it to the yellow/blue (tach output) near the igniter location, and changed my tacho output in tuner studio to Fidle.

I still can't get the dash tach to register. Any help would be appreciated!

 

Connect yellow/blue from igniter wiring to pin 10 on the DB37, even if there is no wire there (not all the I/O was wired on older models). And then set the output back to TACHOUT.

 

Ty sir, that did it!