2001 5.7 GSI flooding

[CampWinkler]

2001 Monterey 262 cruiser with a Volvo Penta 5.7 GSI PEFS.

Engine has 910 hours. It used to run great and get up on plane although it took a while with trim and tilt adjustments.
Now it hesitates on acceleration under load and won’t go faster than 8 knots. We can feel a vibration and smell fuel on the water and If you push the throttle hard it will flood and stall. In the driveway with water muffs on it starts up instantly and idles perfect. Going throttle up (driveway) it will hesitate but then catch up and run smooth.

So far I have replaced; plugs, plug wires, dist. and rotor, MAP sensor, Throttle body sensor, thermostat and housing, temp gauge sensor, oil switch sensor, removed both fuel pumps and cleaned. Removed Throttle body and cleaned. Also ran engine on external fuel can.

All of this had no change.

 

[muc]

I can think of a couple of things.

Maybe you too much fuel pressure? Maybe the screen in the fuel pressure regulator is plugged? Might be good to test the fuel pressure.

Maybe you have a sensor that's giving the ECM bad info and it's adding too much fuel? Might be good to hook up a scan tool and check the values.

Maybe it's time to do testing instead of parts replacement. 30 years as a marine tech, got a lot of brand new parts --- bad in the box --- .

Just surprised someone would replace all these parts without doing the basics, compression test? Lots of those year engines liked to tulip the valves, especially in an under powered hull.