Hello, i have trouble with my Volvo penta V8-300-C-A engine, after it starts and i run for about 1 mile the check engine light comes on blinking for about 30 seconds-1 minute, the engine goes into limp mode (limited power and revs) then after 1 minute the light goes off and the engine runs normally for about 1 mile and after that engine light comes on so i got the boat to be tested by a local service and the guys there had no clue about what to do or even to read the stored errors. What should i check, what should i do?