MBP always boots in removed windows 7 EFI partition

Question

Hi all,
i have a strange issue: after trying desperately to install windows 7 alongside Yosemite on an early 2011 MBP i gave up and deleted the bootcamp partition.
But now it always boots into a windows blue screen of death, even after i make yosemite the startup disk in system preferences.
I always have to start up with the ALT key and am regularly confronted with the blue screen when i forget.
Booting with the ALT key gives me 2 choices: OS X and 'EFI boot'
Windows is haunting me after i deleted it and come to think that i only wanted to try it out because i could. **** you Windows.
It tells me that windows cannot start and it needs repairs, which is obvious because i deleted the windows partition.
Something tells me that it has something to do with the EFI partition where some windows software has to be installed, but disk utility won't let me delete the partition, because it thinks it's the OS X EFI.
Is there a way to restore the EFI partition to a proper OS X partition or how do i delete it and how?
Thanks in advance for your time and effort,
Best of regards,
-sander
Volume layout:
gemeengoed:~ sander$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *250.1 GB   disk0
   1:                  Apple_HFS                         209.7 MB   disk0s1
   2:          Apple_CoreStorage                         249.2 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS ssd 250                *248.8 GB   disk1
                                 Logical Volume on disk0s2
                                 xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
                                 Unlocked Encrypted

Answer 1

tried it and still no go. Have downloaded rEFIt and try and fix it from there. rEFIt analyse gives me this:
thanks for your brain time though.
*** Report for internal hard disk ***
Current GPT partition table:
#      Start LBA      End LBA  Type
1             40       409639  Mac OS X HFS+
2         409640    487127591  Unknown
3      487127592    488397127  Mac OS X Boot
Current MBR partition table:
# A    Start LBA      End LBA  Type
1              1    488397167  ee  EFI Protective
MBR contents:
Boot Code: Unknown, but bootable
Partition at LBA 40:
Boot Code: None (Non-system disk message)
File System: FAT32
Listed in GPT as partition 1, type Mac OS X HFS+
Partition at LBA 409640:
Boot Code: None
File System: Unknown
Listed in GPT as partition 2, type Unknown
Partition at LBA 487127592:
Boot Code: None
File System: HFS Extended (HFS+)
Listed in GPT as partition 3, type Mac OS X Boot