Problems with 4.3 MPI Mercrusier, Help!

[Wyomingman]

I have a 2002 4.3 MPI Mercrusier. I had it out over the weekend and I noticed a buzzing sound coming from the engine compartment after I shut the engine off. It sounded like a pump running. It was not the bilge pump. The noise would not stop even after I shut the master power off. I had to disconnect the battery to get it to stop as it did not stop for over an hour. The boat started and ran fine then I stopped and again the same noise and again I had to disconnect the battery to get it to stop. If I kept the battery unplugged for about 10 minutes the "buzzing" noise would not come back on again when I hooked up the battery.

After I did this the motor sputtered out and then died. The boat would not start. It would try and sputter and then die after about 1-2 seconds.

Anyone have any ideas what this is????

 

[Don S]

Re: Problems with 4.3 MPI Mercrusier, Help!

Sorry, I can't hear it from here. Makes it real hard to identify.
I would suggest you get your ear down there till you find what is making the sound. Then post a picture and we can tell you what it is.

 

[Wyomingman]

Re: Problems with 4.3 MPI Mercrusier, Help!

I really can't tell where the noice is coming from but it seems to be the back of the motor. The hoses that go into the fuel/water seperator seems to be vibrating so maybe it has something to do with the fuel system???

 

[MikDee]

Re: Problems with 4.3 MPI Mercrusier, Help!

It could be the electric fuel pump, on the way out

 

[Bondo]

Re: Problems with 4.3 MPI Mercrusier, Help!

I really can't tell where the noice is coming from but it seems to be the back of the motor. The hoses that go into the fuel/water seperator seems to be vibrating so maybe it has something to do with the fuel system???

Ayuh,.... It Could be,....
You've got to identify Exactly what it is,... Then We can tell you How to fix it...
The fuel system should be controlled by the Key,...

There are Manuals covering that, Up in the Adults Only section at the top of the forum...