5.7GSI PEFS Fuel Cell/Low Pressure Pump Issue

[Fini]

I'll try to make this simple as I've read many posts in this forum and they are extremely helpful and appreciate everyone's input. My problem does not seem unique based on everything I've read.
I bought a boat that I believe wasn't operated much in the last few years but have no idea of knowing. The boat has 61 hours on it and is a 2001. That's good but this is bad:
The high pressure pump whine occured the first time out. It actually went out so I replaced it. Knowing that this wouldn't solve my problems as the whine was probably due to starvation, I disassembled the fuel cell carefully and found the inlet screen to the low pressure pump filled with paint from the housing. The paint was flaking above the float so I removed all the paint and clean the inlet screen. Boat ran much better but get's up to 4000 RPM and then slowly bogs down and will run all day at 3000 RPM. I suspect the low pressure pump is beyond recovery with paint and fuel gunk internally. I've replaced the fuel/water seperator 3 times and inspected the tank. No debris in tank, anti-syphon valve is good, fuel pressures are good and vaccum is good (checked only at idle). Replaced the plugs but did not check compression. Engine runs great at idle and when not under load but like I said, the RPM's drop once I get around 4000-4200 RPM.
From reading many of these posts I think a new fuel cell assembly will fix the problem but would prefer to only change the low pressure pump.

Question: There are many low pressure pumps available for Volvo VP's but where can I find one for this engine? Can I use a Sierra pump that has the correct PSI?
5.7GSI PEFS S/N 4012025441
Any help in locating a low pressure pump would be appreciated or if you have any troubleshooting suggestions for the engine bogging down above 3000 RPM under load, please let me know. I think I'm on the right path but I'm an aircraft mechanic not a marine mechanic!
Thanks to all, very informative forum!

 

[Don S]

Re: 5.7GSI PEFS Fuel Cell/Low Pressure Pump Issue

Have you checked the pressure on the fuel pumps when it boggs down to verify there is a problem? If you have the proper pressure, I think changing the pump would be nothing more than a way to spend money and fix nothing. Besides, the complete fuel cell needs to be changed on that model.
I would also have the 2 injectors tested, if there was dirt and paint in the pump screens, you can bet that some of the finer particles got through and into the rest of the fuel system.
The fuel cell replaces as a complete unit and there is no Volvo replacement for the low pressure fuel pump.

 

[Fini]

Re: 5.7GSI PEFS Fuel Cell/Low Pressure Pump Issue

Thank you Don,
No I have not checked fuel pressure when it bogs, this will be my next step. If it was an injector issue, wouldn't it be apparent at all power settings, both loaded and unloaded? If the fuel pressure is good when it bogs, do I move upstream to the pressure regulator? I'm not a fan of shotgunning parts unless I have known good spares laying around, which I don't, so I will continue to try to isolate.
I failed to mention that the Volvo dealer said there were no codes, vacuum confirmed good (not under load) and fuel pressures were good (not under load). They wanted to replace the fuel cell.
If the injectors can fail under load, I will remove those and have them tested.
I'm curious what makes the low pressure pump on the fuel cell so unique that there are no carter/sierra pumps that can be substituted. Is the GPH/fuel pressure unique to that one pump or is it a proprietary issue with Volvo so that they can sell more fuel cells?
Thanks!

 

[Fini]

Re: 5.7GSI PEFS Fuel Cell/Low Pressure Pump Issue

Well I found the smoking gun. I took apart the fuel cell and found the inlet screen to the low pump gummed up but I also found the float in the fuel cell sticking against the housing. It was stuck so the needle valve would never seat. I took the float out and removed about 1/16 of the side of it and reinstalled. It now has clearance.

Took the boat out today for 6 hours and engine opeartion was flawless up to WOT. I drove it up and down the lake waiting for a bummer but it never happened. I'm confident I had two issues: 1) low pump inlet screen and 2) stuck float in fuel cell. It doesn't help that I found yet more paint that had to be removed in the vapor chamber. I removed all paint that was accessible internal to the fuel cell and replaced all the O-rings.

If you have any mechanical abillity what's so ever, the fuel cell is repairable (but the low pressure fuel pump cannot be purchased/found). 6 torx screws, 4 o-rings and two o-rings for each pump. The large o-rings on the vapor chamber are 2 3/4 OD x 1/16th thickness and 2 1/2" OD x 1/16th thickness. You'll need two of each.

Don't waste your money buying a new one unless the housing is damaged or the low pressure pump is bad. Other than that, there isn't anything complicated to the fuel cell itself.

Hope this helps others in the future, other posts in this forum swayed me to overhaul the fuel cell on my own rather than purchase a new one.
The key things I learned was to check boat side fuel supply, low and high fuel pressures and all the easy stuff before taking apart the fuel cell.

The fuel cell can be removed in 10 minutes and overhauled in 1 hour.