6L Marine power EFI.... original complaint was a loss of power on acceleration, boat was pulling fine and then all of a sudden the engine would drop to an idle.... if you immediately pulled the throttle back and then advanced it ... off you go.... if not and throttle was left in position there was backfiring thru the intake.. this was intermittent but got progressively worse. Next symptom was when the engine was heated up and at idle, the engine would start to stall... if you feather the throttle you could bring it back. Lastly, after the engine would start to stall and if you kept it going, there was no throttle response.... move the throttle but nothing.... turn off the ignition and restart....you have the throttle back. As a side note.... this engine would never start without advancing the throttle, hot or cold. I took a guess and replace the throttle body which cured the throttle advance, starting issue... but the idle stall and loss of throttle continues. I am not sure on the loss of power because I wanted to get back to my mooring... Thoughts?