I tried jailbreaking my friend's iPhone 3gs with new bootrom on 3.1.3 with limera1n. It was not previously jailbroken. Now it's stuck on the Apple Logo screen. Is there any way to get it out without restoring to 4.1?
You can't use limera1n with iPhone OS 3.x.x
So, no there is nothing you can do without restoring. You can restore from a back up, that way, I don't think iTunes will force you onto 4.1? I am unsure about this.
That's false.
You will either need shshs to restore to anything but official 4.1 or use Pwnage to restore to custom 4.1 so you can unlock.
Will I be able to restore to a custom firmware even if the phone was not previously jailbroken?