Another whiner...fuel pump that is.

[lonewolf41]

Bought a 5.0OSi-E (model 3869270, serial 4012110198) to re-power my boat. Wanted to start it up before installing to make sure it runs OK, etc. It would barely start and then die. Began to hear a whining from the fuel pump. Went out a hour later to try again with pressure tester connected to the fuel rail. This time it started up and ran well. Fuel pressure was around 60 psi. After a couple minutes, the pump started whining and the pressure began dropping until it got to around 15 psi and the engine died. The pump was hot to the touch. I know there are multiple posts on here about similar issues so I took off the high pressure pump and the screen had maybe 8-10 small particles in it, but it was not clogged by any means.

I had another high pressure fuel pump from another motor (the one I am replacing) so I put it on there and the pressure with this pump would run about 80-85 psi and then it started to whine, loose pressure, etc after a pretty short time. It was also hot to the touch. One other side note...with the original pump, the pressure would drop to 0 after the motor stopped. The "new" pump would maintain pressure after the motor was shut off.

So my question is will replacing the high pressure pump fix this or is there some other underlying cause causing the pump to act this way? I.E is the pump getting hot causing it to fail (poor cooling), or is because the pump is failing, it is getting hot. Neither pump was plugged, but both got hot. Both pumps were used. I think the one that came with the motor had a little over 100 hours on it. Not sure about the one that came with the boat. I just don't want to start throwing parts at it.

TIA,
-Keith

 

[bruceb58]

How's the pressure on the low pressure pump?

 

[kmarine]

I have had nothing but trouble with carter fuel pumps on efi Volvos multiple boats come in with water in fuel that destroys these in seconds. I have added larger additional water separating fiters on all Volvo efi in my shop.

 

[Taz59]

This is worth a read
http://forums.iboats.com/forum/engi...w-approach-to-the-volvo-penta-fuel-cell-5-0gi

 

[BRICH1260]

Is your pump cooling system working properly. The water circulating in the canister jacket helps cool the high pressure pump as it rests up against it. Not sure that it is the answer to your problem but it might help. Make sure that water flows through from one hose to the other. If you boat in salt water sometimes calcium deposits can clog the output and inputs.

 

[lonewolf41]

I couldn't find anything in my manual about testing the low pressure pump, but from what I gathered, you hook the tester to the port at the bottom of the fuel cell. Here is a couple of videos of what I did and the results. In this video, https://drive.google.com/open?id=0BwnuuOR-sHTUWExPRmtEWHJmNjg

I have both pumps hooked up. In this video, https://drive.google.com/open?id=0BwnuuOR-sHTUbnJpUHpMOXgyaTg

I unhooked the high pressure pump so I could just hear what the low pressure pump is doing:

Either way, with both tests, the fuel pressure gauge never moved. I assume this means that I need the low pressure pump at the least. It didn't sound bad, but never made pressure from what I could tell.

Anything else to check?

TIA,
-Keith

 

[bruceb58]

You should be getting 6 or 7 PSI from the low pump.

 

[lonewolf41]

OK, I rebuilt the fuel cell with all new pumps. I still don't get any reading at the schrader valve, but I may not have the correct adapter for it. So I hook the gauge up to the fuel rail and only running the low pressure pump (high pressure pump unplugged), I get 12psi at the fuel rail so I am assuming that is an accurate measure of the low pressure pump output.

Now, however, I am getting 90-100psi on the fuel rail. If the engine is not running and the fuel pumps start up, the pressure jumps to 90+ psi, but as soon as they turn off, the pressure drops back to 40-50psi. I looked through the manual but could not find anything on troubleshooting high fuel pressure. I assume it related to the regulator, but what is the procedure for diagnosing and repairing?

Thanks,
-Keith

 

[lonewolf41]

I went ahead and pulled the pressure regulator and, sure enough, the screen was caked with debris. I cleaned it off with carb cleaner and reinstalled and now am getting 50-55 psi at the fuel rail while running. So hopefully, this puts a pin in my fuel issues. Thanks for all the help and feedback.

-Keith