The fuel pump whine....

[Big One]

1998 Seaswirl Striper 5.7GSi I/O

Hello everyone!! Not sure if this happened to anyone here, but I use to get a whining noise coming from the low pressure fuel pump. The pump would actually shut off but we figured out the problem. There was water in the fuel tank. So we had the tank emptied and put in new fuel with a new racor water separator. The whining noise was still there, however the fuel pump never shuts off. If I rev the engine then the noise will go away, but its just unnerving while out in the ocean. So I took out the Racor water separator and the noise is gone. I believe the water separator was starving the fuel pump by giving it too much resistance. Does anyone have this issue? Is there something else we can install that doesnt make the pump whine? Any input would be great. Thank you!

~Big One

 

[Don S]

Re: The fuel pump whine....

I would suggest you do some fuel pressure checks on the low and high pressure pumps. Also check for air leaks in the fuel system between the tank and fuel pump.
My guess is you are sucking air into the system. Possibly from using the wrong type hose clamps (and hose) between the tank and pump.
You need to use type A1 fuel hose, and use the narrow (1/4" wide) mini hose clamps. The bigger (1/2" wide) hose clamps tend to flatten the hose and allow air to leak into the fuel pump instead of fuel. Even worse if using thin walled non marine fuel hose.
You could also have problems with the pickup or antisiphon valve, check it out like this.
http://forums.iboats.com/showthread.php?t=167561

 

[Big One]

Re: The fuel pump whine....

Don S,

Supposedly our mechanic checked for fuel pressure and it's at the right pressure. He also changed the fuel hose and put new clamps on. I'll check the size clamps to make sure. Thank you!