This is a common fault.
My a98 touch screen packed up, but as it was just a few weeks less than 3 years old, Raymarine replaced it foc.
There's not much you can do I'm afraid.
I kept my a98 as a spare, as I now have an es12. It's only been used once for a week since it was replaced and I...
Are you sure you've timed it right. There are two sets of timing marks on the pump pulley for turbo and non-turbo. Other thoughts are air leak from aftercooler, losing boost pressure or exhaust partially blocked.