From your ESX configuration you should be able to click on storage adapter. Then rescan from there. If you don't see the path to the storage it won't work. iSCSI is tricky..
You MUST have the credential corrects, and you MUST have the exact name for the target in the iSCSI initiator to match the storage controller AND you MUST have the storage controller configured to allow the ESX iSCSI initiator configure for it to connect.
If any or all of these are not done, you will not be able to connect. Keep it simple (for now) disable chap or authentication, just let it connect with no login (you can always change it later). Also configure the firewall (for ESX) to allow the NIC you created with vKernel to allow the iSCSI to be able to connect as well.
Also with the new servers SOME NIC controllers need to be bound to the controller via iSCSI, but the ESX host uses a iSCSI iniator software that ALSO must be configured, and the HBA must be bound to that iSCSI initiator as well. Doesn't this sound like fun?
Serioudly it's not as hard as it sounds.. but it does mean checking a few things. Screen shots help a lot.. just FYI