This sounds like a ICV that is completely closed/seized up to me. I was having a similiar problem with my old 2.5l engine and it was mainly due to the ICV not opening and closing properly. Have you pulled codes by chance? Also, check vacumm hoses. The scraping sound has me confused though.
I forgot to add. CHeck your MAF because this could cause a similiar problem and check your throttlebody. I'm wondering if it's sticking or something and not able to open and close properly itself. This could cause too much fuel and not enough air in cause it to flood which could be happening.