150hp efi limp home mode

[hangemhorns]

i have a 1993 mercury 150hp EFI. when outside temperatures are above 90degrees after boat has ran awhile, motor goes into limp home mode..i have changed water pump impeller, and thermostat...what is causing this....

 

[CharlieB]

Re: 150hp efi loap home mode

Re: 150hp efi loap home mode

93???
Limp home mode??????

Have you checked spark on all cyl's when this happens?

You may be having a heat related ignition problem, possibly even a vapor lock fuel supply problem.

Can you check fuel pressure at throttle when this occurs?