Proper gap is ~.030", so that's not the problem.
The wire you're looking for is orange with silver hash marks from the dash harness (I assume it's an S13), and goes to the ECU to give +12V whenever you're cranking the car. The car
should start without it, if you pump the gas and crank it a few times, so I'm guessing that's not the problem. Anyway, check to make sure you have +12V at all the applicable pins using the wiring diagram:
The pin locations are from
THE BACK of the ECU harness most of the time - you can check because the '100' pins are physically larger than the rest.