Oil Pressure / Fuel Pressure Issue?

[Too Many Toys]

I have a 2000 volvo penta, 5.7L Gsi. If the oil level is overfilled by any amount can it cause the fuel pump to reduce the amount of fuel pressure? I was just curious about this because with a fuel pressure gauge installed on the high pressure pump at 30-35 mph the engine starts to bog down, starve, as soon as this happens, the fuel pressure drops from 30 psi to 20 psi. I hate to go spend the $700 plus on a new fuel pump setup and that not be the fix. The oil pressure gauge on the dash reads fine and the pressure reads fine through the scan tool. I was wondering about this thinking it could be something other than the pump itself going bad because when leaving the no wake zone one time, it just sputtered and backfired and would not run 10 mph. The next time after removing all gas from the gas tank and adding new gas, left the no wake zone and it throttled up to approx 20 or so without any sputtering on takeoff. The next weekend, leave the no wake zone and it sputtered like it did the first time we took it out. Any more thoughts or ideas would be greatly appreciated. Thanks Mark

 

[Bt Doctur]

Re: Oil Pressure / Fuel Pressure Issue?

The oil pump pressure has no bearing on fuel pump pressure

 

[180shabah]

Re: Oil Pressure / Fuel Pressure Issue?

Go to the adults only section and check out "How to troubleshoot your boats fuel system".

Don't jump straight to the fuel pump.

 

[bruceb58]

Re: Oil Pressure / Fuel Pressure Issue?

There is an oil pressure switch that closes a relay that goes to your fuel pumps. Easiest way to diagnose that is to just bypass the oil pressure switch or the relay itself.

 

[freelancer]

Re: Oil Pressure / Fuel Pressure Issue?

See my June 5th posting "how to replace a low pressure pump on a 2001 Larson 270 with 5.7 GSI VP".
A tune up didn?t seem to help. I removed my fuel cell and took it apart; I found that my low-pressure pump was caked up pretty badly at the screen. My high-pressure pump was wining pretty badly all last season so I replaced it in the spring; the screen on the high pump was not as bad. But in the end it may wind up being the low-pressure fuel pump after all, which as far as I know only comes as part of the whole fuel cell. We'll see when the fuel cell arrives, its on back order from VOLVO PENTA and may be available some time the last week of June. Your not supposed to take apart the fuel cell but I had already ordered one any way, so I did. Good thing because while putting it back together, I trashed the o-rings on the vapor chamber and wouldn?t have been able to use it anyway. I have been reading up on my problem and there were some fellow Captains that had success after replacing the Fuel Cell, I hope I'm one of them, if not its back to the drawing board. You may want to do some more diagnostics before you go spending that kind of money on a fuel cell. Freelancer.

 

[freelancer]

Re: Oil Pressure / Fuel Pressure Issue?

Well, I received the new fuel cell from Volvo Penta today and installed it on my boat. After two tries she turned right over, got out on the Delaware and eased her up on a plane. I ran the engine for about 45 minutes at various RPMs, WOT and even sat and drifted in idle for while. It seems that the new fuel cell was the fix for my problem. I haven?t been able to get up to 5000 RPMs since last fall but I did today. From this point forward I will be proactive regarding my fuel system and monitor it a little closer, I will certainly make sure I supplement the fuel with the correct additives to help keep the fuel fresh and in the proper condition to burn through the engine. I just wanted to pass it along, thanks for all the help and advice. Freelancer

 

[Proline26]

Re: Oil Pressure / Fuel Pressure Issue?

Hey Cadet,
I have the same engine and same issue. I have also taken the fuel cell apart and cleaned the screen and tested the pump. Everything looked good so I bought new Viton orings because thats what it takes. Installed it and felt like I had fixed the issue. Kast week I put her in the water went out and past the beakwall throtled up and bam flat on her face past 2500rpm. All the psi start to drop and she startes to sputter. And yes I have checked everything new cap rotor fuel, filter checked sensors all the checks that as a mechanic that I am need to do. So now I am debating to buy a fuel cell or bypass that and go with a custom system that commercial boats run. A high pump and a low pump with a remote filter system. All coast guard approved pumps. I dont know I just hate to spend that much for a fuel pump.

 

[freelancer]

Re: Oil Pressure / Fuel Pressure Issue?

Proline26, I know how frustrating this problem can be. I'm still not sure if two weeks or a month from now I'll be revisiting the issue. In my attempt to salvage the old fuel cell, I purchased a new hi pressure pump ($250) and was on my way to trying to replace the low pressure pump but the guy on the other end of the phone couldn?t convince me that he was selling me the same part I needed. So in the spirit of salvaging the season and airing on the side of safety, I got the new cell. After I took the cell apart, I wasn't confident that I wouldn't have a mini space shuttle incident in my engine room, even though I read that some skippers have put it back together successfully. I plan to put as many hours on the engine needed to put some fresh fuel in the tank and see how it goes. Let's see how Too Many Toys does, either way keep at it Capt., I would like to know how you make out. Freelancer

 

[RGT]

Re: Oil Pressure / Fuel Pressure Issue?

Go to the adults only section and check out "How to troubleshoot your boats fuel system".

Don't jump straight to the fuel pump.

how do I get to the adults only section to find "How to troubleshoot your boats fuel system".

 

[freelancer]

Re: Oil Pressure / Fuel Pressure Issue?

open up the link for "Mercruiser, OMC, Volvo & other I/O & Inboard Engines & Outdrives" and it's the 1st thread. The fule test link is #3 in the list of items. Freelancer