2004 Merc 5.0L MPI (Engine serial # OWO18920)
Engine has been extremely low on power (sometimes, won't even get up on a plane) and seems starved for fuel. If I feather the throttle up gently about 100 rpm at a time, it will get up and go after a few minutes, but is still low on power and will only go about 25 mph as opposed to the normal 36-38 mph it can do at WOT. Replaced the LP pump and filter/separator. Didn't fix it. There was a good deal of water in the separator (75% water, 25% gas), but I replaced it with at new separator (which hasn't filled up with water..... yet) and the problem continued.
In replacing the filter, air got into the system, so the engine started for a minute, died from the air and then wouldn't restart. The HP pump wouldn't prime itself. I could hear it pumping air and not grabbing any fuel. I used the pressure test schrade valve to let some of the air out as the pump ran, and I was finally able to "bleed" out some of the air and I could hear the pump finally grab some fuel. The boat then started and idled just fine and would rev up just fine, but still won't put out the horsepower to get up on step and go. You can feel it trying every once in a while for half a second, but then just can't do it.
Is the failure to prime itself an indicator of a problem with the HP pump?
Is there another filter before the HP pump that could be clogged and preventing the pump from priming?
If water got by the first separator, is there someplace else it could cause my problems?
Is there something else painfully obvious that I might be overlooking?
Why won't my boat just work????
Thanks,
-Nick
Engine has been extremely low on power (sometimes, won't even get up on a plane) and seems starved for fuel. If I feather the throttle up gently about 100 rpm at a time, it will get up and go after a few minutes, but is still low on power and will only go about 25 mph as opposed to the normal 36-38 mph it can do at WOT. Replaced the LP pump and filter/separator. Didn't fix it. There was a good deal of water in the separator (75% water, 25% gas), but I replaced it with at new separator (which hasn't filled up with water..... yet) and the problem continued.
In replacing the filter, air got into the system, so the engine started for a minute, died from the air and then wouldn't restart. The HP pump wouldn't prime itself. I could hear it pumping air and not grabbing any fuel. I used the pressure test schrade valve to let some of the air out as the pump ran, and I was finally able to "bleed" out some of the air and I could hear the pump finally grab some fuel. The boat then started and idled just fine and would rev up just fine, but still won't put out the horsepower to get up on step and go. You can feel it trying every once in a while for half a second, but then just can't do it.
Is the failure to prime itself an indicator of a problem with the HP pump?
Is there another filter before the HP pump that could be clogged and preventing the pump from priming?
If water got by the first separator, is there someplace else it could cause my problems?
Is there something else painfully obvious that I might be overlooking?
Why won't my boat just work????
Thanks,
-Nick
