Whinning Fuel Pump

[sbeausol]

I noticed a very loud whine on the fuel pump of my 1996 5.0L Volvo penta powered Four Winns. More often than not when it whined, it stalled. I was able to limp home, but I am thinking i obviously need to replace the fuel pump. I would prefer to do it myself, can anyone give me an idea of the degree of difficulty here? (i've done the impeller on my outboards and various other maintenance so i would consider myself reasonably handy).

Thanks for any input...

 

[Bondo]

Re: Whinning Fuel Pump

Ayuh,.... It's not to hard,.... Tubing Wrenches make things go Easier...

How old is the Fuel Filter,..??

 

[sbeausol]

Re: Whinning Fuel Pump

not sure how old the filter is, the motor is a complete rebuild w/10hours on it, i guess it makes sense to start with the filter and move to the pump afterwards. I've read a bit about high and low pressure pumps, that a concern on this boat? I know it would be easier to answer w/model number but I'll look that up. Pretty sure its a 5.0L EFI mated with a penta sx outdrive

 

[Don S]

Re: Whinning Fuel Pump

Those pumps get very noisy when run dry. So, why is it running dry? Air leak from loose clamps?

Pretty sure its a 5.0L EFI mated with a penta sx outdrive

Pretty sure doesn't cut it. An EFI engine has 2 pumps, and a carbed has 1. They cost in the hundreds to replace. So you might want to be sure of what you have and give exact information.

 

[sbeausol]

Re: Whinning Fuel Pump

thanks don, will do more investigating over the next few days. Its def an EFI engine, i've got the book somewhere so once i dig that up i'll relay more info. As for the whine, it is pretty intermittent and i went through several cycles of start and stalls before she finally limped home, sometimes she powered through the whine sometimes she didn't.

Sounds like i should start w/the fuel filter then check all the hoses, then check the pressure on the pump? Is that hard ( i know i'll need a high pressure fuel gauge)?

thanks again for such a great resource!

 

[Don S]

Re: Whinning Fuel Pump

If you have a bad low pressure pump (as in not working) then your high pressure pump could be trying to pump air. Get your manual (Sure hope it's oem and not seloc or clymers) and a pressure gauge and start checking.

 

[sbeausol]

Re: Whinning Fuel Pump

Ok i found the book, it looks like the motor is an 5.0 Fi Ford

 

[chiefalen]

Re: Whinning Fuel Pump

check the fuel pickup filter,vent,ant-syphon valve.

 

[sbeausol]

Re: Whinning Fuel Pump

Ok so i had some time sat to spend on this issue. Picked up a pressure gauge and measured my low and high pressure sections on the fuel system. High pressure spec'd out perfect, low pressure didn't register. In addition the low pressure pump was extremely hot to the touch. Decided to replace low pressure pump and picked one up for $219 put it in and tested pressure again. Now the low side was also running up to spec and the pump didn't get warm at all to the touch. Ran the boat for about 1 hr without issue so i am thinking the problem is resolved.

Thanks for all the input, this forum is great!