Q - 2005 6.0 Ford. I am having cold engine missing unt il it warms up and then seems ok. Also when pulling boat up steep hills the turbo will turn off and I get a fault saying over boost. I think due to batteries being run down and then trying to start with these dead batteries has damaged my injector module. Can you suggest other problems I might have.
A - I would start by checking to see if you have any codes present and checking the FICM voltage. If you are getting low voltage or FICM codes, that could be the cause of your cold missing issues. If that all checks out ok, you probably have some stiction on the injectors. I would suggest a couple of bottles of Rev X to help clear it up.
As for the overboost, the turbo maybe sticking closed and causing to much boost. It might be a good idea to pull it off and clean the unison ring. If it can't open all the way up, it will cause the turbo to produce more boost than what the computer is happy with.