When I turn ignition1st time nothing happens, not a sound...then it fires right up on 2nd turn of the ignition. After it fired up on 2nd try, I turned it off and it fired up on 1st try.

 

I have been advancing timing the last 2 weekends, this problem started after my last timing advance on Sunday 1/13.

 

15 sound to far i think 12 is about max for your setup i have a 306 build and i dont run higher then 11 or 12

 

It could be your starter relay or ignition switch going bad.
Also if an automatic, could be your neutral safety switch or if stick could be your clutch switch.
Get it to not crank and you can check it out.

 

Any updates on this?

I'm kinda having the same issue, just now it won't start at all. I've checked the starter relay... I was going to check the clutch switch today, but it's snowing too bad to work on the car outside.

 

I did that for a couple of days after I advanced timingand now I have no starting issues.

 

sounds like your car doesnt like to much advance. mine used to do the same thing back it down 1 or 2 degrees it should help it. 15 is pushing it just a bit you might have some top end pinging. mine is set at 14* no problems fires up right away everytime even when its 5* out in the morning