After running the boat friday the port motor stalled and wont restart. It will run on starting fluid. I swapped the computer with my other motor and still no luck.

Sounds like a fuel pump failure, you're out of gas, or somewhere in-between. The ECM is the most unlikely culprit.

I agree, if it runs on starting fluid then there's a fuel problem. Pick up an EFI fuel pressure gauge and see what, if any, presure you'r getting. Could be as simple as the fuel cut off switch (oil pressure activated) or a pump gone bad.

Two questions, when you turn the key on do you hear a pump run? If yes, unplug the lift pump at the fuel sep filter and try again. Do you hear a pump run on key up? If not, the high pressure pump is bad.

John