Having killed 2 MEFI 4B ECU's and having spoken to Marine Power a few times over the years they recently mentioned oh yeah we know why they are dying and sent me this GM bulletin which was from 2002, 4 years before our boat was even made..
In summary fix your wiring before you need a new ECU which is basically unobtainable..
Link to changes here
https://drive.google.com/file/d/1eo9...ew?usp=sharing
We did the modifications inside the black box behind the ECU.
In summary fix your wiring before you need a new ECU which is basically unobtainable..
Link to changes here
https://drive.google.com/file/d/1eo9...ew?usp=sharing
We did the modifications inside the black box behind the ECU.