http://doc.pfsense.org/index.php/Boot_Troubleshooting
set kern.cam.boot_delay=10000
boot
This worked for me. One problem I had when originally troubleshooting, escaping to the loader prompt, setting a value, and rebooting was probably because I'm pretty sure I was entering the command reboot which as far as I could tell was erasing my changes and completely powering off and rebooting. The above documentation referred to the "boot" command which didn't do this and kept the changes I had made and worked.