I'm with Pukka on this.
My Eunos had a period where it would just cut out at random times, I checked everything, it sent me mad. By chance I found I could make it cut out with having the steering wheel at a certain angle, it was a loose earth on the immobiliser and it looped down near the steering column, when a joint on the column hit it, it would move it just enough to cut it out!
Nipped up the earth and it was sorted.

My mark 1 did the same, warm up then cut out while driving. It was the optical sensor in the distributor, cleaned and replaced that then it was all good. Have a look on US s12 forum I posted some pics of my dizzy on there to give you a better idea

you got linky to the us s12 dizzy post please?