There are lots of things that can cause your problem. Here is a link that will give you a great idea of what the problem might be ;
Kennedy Diesel. And John Kennedy is one of the best in the business - he knows his stuff.
And if that isn't enough enough information, just google 'P0076' (those 0's are numeric zeroes, not alpha o's) and you will be up for a couple of days reading about the problem and possible solutions.
IF your injectors need replacement, that is likely the fix. If they're verified to be OK (not bypassing too much fuel at high temps), then the approach I wold use would be to install a lift pump with additional filtration. This supplements the existing system, makes it so that the problem is less likely to happen.
