MicroSD card won't return any data on read command
Posting this answer as an excerpt of the comments, since the issue seems to have been resolved.


  The registers in the SD card can be more tolerant to voltage drops
  than actual memory access, so this could be a power issue, perhaps you
  can check with your scope that the voltage supply to the card stays
  within 2.7 to 3.6 V the whole time. –  apalopohapa
  
  @apalopohapa Success, Looking at the input voltage, it was fine up
  until the ACMD41 init, then dropped down to 2. My boss pointed out a
  diode on a different page of the schematic that should have been tied
  low. Now I am reading everything correctly, and can continue. I'm just
  frustrated because time and time again I've had to tell myself to
  check power when having problems, and I can't just assume it's not an
  issue because it works half the time. I appreciate all your guys'
  help. –  farraman