I'm. having similar issues since about the same time. difference is that my car doesn't drive yet. I had the car running and starting first time fairly reliably. but it got harder to start and one day turned off while it was running and now doesn't start at all.
I have gotten a new CAS which I've had no luck with do far but today I did hear a buzzing noise similar to what you described coming from. somewhere. I'm about to open up the ecu to give it a look too.
I'd love to hear if you had any luck. with anything. I've gotten a set of r33 s2 coils coming and I'll bypass the rb20 ignitor which may help but if I find a fix I'll also keep you posted :)
