Initially no spark, now lumpy idle / miss firing / won't idle without stalling

Hi, I bought a turbo’d NB last week which has been bit of a disaster so far, the car is turbo’d and forged.

When I picked it up and test drove it was perfect, the day after getting home it wouldn’t start…

  • Replaced the battery, still no start but crank
  • Checked the plugs, had no spark
  • Replaced the leads and plugs – horray she starts.
  • I went for a 20 miles drive without any issues but did notice a bit of hesitation sometimes at lower revs before coming onto / when starting boost.
  • Went for another drive and 2 minutes down the road the car is juddering under acceleration, sounds like a Harley, won’t hold idle and smells like fuel.

This video here is pretty much what I’ve got Mazda Mx-5 Miata - rough idle then engine stops [SOLVED] - YouTube

Now, when I replaced the plugs and leads I did think to myself that I’m surprised that fixed it… it seems there is more going on.

The video I linked said the crank position sensor fixed their issue. I do have a genuine new one of these, but wondering if there is anything else I should be looking at?

I will try the crank sensor, and plan on getting another set of coils to test with.

The car has been tracked a couple of times without issues before I owned it so it can take the abuse, for some reason it just doesn’t like me!