5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video)

[perna00]

1995 5.0 OMC (ford) efi multiport injection. Is this pump whine excessive or normal? The low pressure pump is very hot also. I have a miss above 2,750 rpms.

http://youtu.be/ml4DW4uM63o

*MODS: I will combine this with my other thread in a day or two. I just need some input. Thank you if this is acceptable.

 

[Don S]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

Air is what makes pumps noisy. aka lack of fuel. It's even sounds choppy like air and lack of fuel.
Hook up a remote tank to your engine connection (on the filter inlet) and see if the pump is still noisy. If so, pull both pumps and look at the intake screens on each. You will need new orings and gaskets for the VST tank. Don't even think about trying to reuse them.

 

[perna00]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

I'll try it on the next few days. Excuse my ignorance but what does vst stand for?

 

[Don S]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

Vapor Separator Tank.
That little housing (tank) the high pressure pump is sitting on top of.

 

[perna00]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

I'm going to test out the system with an external tank today. Is there any other areas that could be allowing air to enter the fuel lines without any fuel leaks? With the lines being hard stainless lines on the engine side, I believe any leaks would make fuel bleed out. If this is the case, the only place that could be leaking is the fittings attaching to the fuel tank and the inner pick up tube. . . correct?

 

[Don S]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

The air leaks will have to be on the suction side of the fuel system. As I was saying, it may not be air getting into the system as much as fuel not getting to the high pressure pump. That is why I suggest checking the screens in the pumps for blockage. Since it's only the high pressure pump making noise, it is probably the one with the plugged screen, but if the low pressure pump isn't getting fuel to it.............

 

[perna00]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

Thanks! I just replaced the low pressure pump and the old screen was perfect. I'll try the external tank first. If no success, I'll pull the high off and check it.

 

[perna00]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

Well, I hooked up a gas can with a 4' 3/8" hose to it. No change in pumps. Even in the driveway the low pressure pump got hot and the high pressure whined very loudly. No change from the two different supply lines. I already replaced the low pressure pump. I'm going to assume the high pressure pump is as bad as the rest of the old boat parts and replace it as well. Autozone sells one (yes it is marine use) for around $100. Hope this is my issue.

 

[perna00]

Re: 5.0 EFI fuel injected engine high pressure loud pump whine, is this normal (video

MODS: I've converted links and info to other thread. You can delete this if desired.