2003 Volvo 8.1 GI-D Fuel Pump Whining

sloch24

Cadet
Joined
Jun 24, 2004
Messages
17
I have a 2003 Wellcraft Coastal 270 with a 8.1L GI-D Volvo Penta Engine. The other day while out fishing, I heard a loud whining sound. I assumed it was the fuel pump because it didn't change with engine RPM. When we returned to the dock, I verified that it is indeed coming from the high pressure pump on the fuel cell.

Yesterday I tested my pressures. I'm running 40PSI on the high side, and 8PSI on the low. One thing I noticed is that the high pressure remains constant after the engine is turned off. The low pressure bleeds off to 0 almost before I can make it back to the engine to see it. Is this normal, or is there a check valve malfunctioning inside the pump.

I removed the cover off of the fuel pressure regulator on the fuel rail and looked a the screen inside. There was very little if any dirt on it. I blew it out, cleaned up some paint that had seeped under the cover (probably not hurting anything) and reassembled. As I expected, the high pressure reading did not change.

I removed the fuel cell assembly and brought it home. I read in another thread where someone was able to disassemble the fuel cell and clean the inlet screens to the pumps. I removed the high pressure pump, and the screen did have some debris in it, but it wasn't clogged as I had expected. I was unable to remove the bottom of the fuel cell to inspect the low pressure pump. I tried tapping it off with a block of wood and a hammer, and it won't budge. Can someone shed some light as to the dis assembly of this fuel cell?

I may be wasting my time, but I would like to check it out. At the dock yesterday I didn't have any whining sound, so the cell must have been full of fuel and the high pressure pump was not cavitating. I still only had 40PSI. Am I looking at a HP pump failure? I see that those are being offered for sale as a Volvo Penta 3588865.

I make it a point to only fill the tank with non-ethanol fuel, so maybe that's why I'm not seeing the paint buildup like others have. The only paint issue that I noticed is where the fuel filter seals. It was all bubbled. I scraped it off, and cleaned it up with steel wool. It's now nice and smooth.

The boat seems to run okay, but I've had an issue since I bought it (in 2009) where it doesn't want to stay running when first started unless you give it a little throttle to keep it running. I'm now wondering if low fuel pressure is to blame for this problem. I'm also not sure if I can reach WOT RPMs. I have a flaky tach, and need to either clean the connections, or replace it, but according to a brochure I found about the boat online, it's supposed to be able to do 45MPH with this engine configuration, and I'm lucky to see 35-38MPH. Now I know they probably over state that number, and that's with a clean bottom (mine's painted) and no weight inside (I always start the season with 188 Gallons of fuel and a full water tank).

Thanks in advance for any insight into this problem.
 

sloch24

Cadet
Joined
Jun 24, 2004
Messages
17
Update:

I re-installed the pump this afternoon. I am still only running about 40PSI on the high side. I replaced both the pump mounted filter, and the water separator that is inline before the pump. I took it out for a ride and didn't hear any pump whining, but it was intermittent, so time will tell.

At this point, I'm assuming that the high pressure pump is just old and worn out. The boat has 950 hours on it, and it LOOKS like it could be the original pump. I bought the boat in 2009, so it's possible that it's been replaced, however, the part number of the pump appears to be circa 2003.

Do these pumps have a specified life? If I don't hear any more cavitation, would it be safe to just replace the high pressure pump, or should I bite the bullet and buy the whole fuel cell. Now that I've had it off, it's not a bad job to replace it, it's just that it's $700, and the high pressure pump is only ~$250

I have not yet performed the boat side tests in the adult only section, but my low pressure is fine, it's my high pressure that I'm having problems with.

I did clean the terminals on the tach before I took it out for a test run. Unfortunately, my trim pump wouldn't work. When I got back to the dock, I found that one of the relays was stuck. After tapping it while energized, it started working again. I did however run the engine at around 4000 RPM for a very short while. I just read that WOT for this engine is 4500. Now that the tach is working, I'll have to test full speed with the out drive trimmed out.
Once again, any help will be appreciated.
 

Thalasso

Commander
Joined
Jan 18, 2011
Messages
2,876
The whine comes from the high pressure side because the low pressure side isn't feeding enough fuel. I think the low side should be in the 15-18 lbs of pressure. And yes the pressure will drop to 0 when you turn the key off. To get the low side (not sure about yours) you need to buy the complete fuel assy. You can buy the high side separate but they normaly don't go bad.
The key to longer life is when you turn your key on let the pumps fill up before starting. A good sign of pump failure is the engine will start stumbling trying to get fuel.
Take the low side pump numbers and look on E-Bay. That's where i got mine a couple of weeks ago.
 

sloch24

Cadet
Joined
Jun 24, 2004
Messages
17
Thalasso,

Thanks for the reply.

Everything I can find online about these pumps states that the low pressure pump should be at 8PSI +/- 4PSI and the high pressure pump should be between 50 and 60 PSI.

You mention to take the low side pump numbers to Ebay, yet you also say that they're not available and the whole cell must be replaced. Did you have any luck just purchasing the low pressure pump?

As of right now, the engine runs fine except for wanting to stall when first started after sitting (a day, a week, more than a few hours). I just had the whine, and that's why I bought a pressure gage. That's when I found out that I'm 10 PSI shy of the low end of the spec.

I always wait for the fuel pump to shut off before starting the engine. I believe the "BEEP-BEEP" is coordinated with the fuel pump running. When the beeping stops, so does the fuel pump.

Thanks again!
 

sloch24

Cadet
Joined
Jun 24, 2004
Messages
17
Okay, I found some interesting information.

Even though multiple engines use this same fuel pump, the 8.1L engines fuel regulator is supposed to run 36 to 44 PSI, NOT 50 to 60. It appears that maybe I just had a fuel filter restricting my low pressure pump. If it doesn't make any more noise, I'm going to assume that the problem is fixed.

I found a post by someone else in another forum that mentioned the VP EFI service manual, page 240 states that the fuel pressure is lower on these engines.

From the Manual:

Test Description
Number(s) below refer to the step number(s) on the
diagnostic table:

2. When the ignition switch is ON and the fuel
pumps are running, the fuel pressure indicated by
the fuel pressure gauge should read 344-413 kPa
(50-60 psi) for 4.3, 5.0, and 5.7 models and 248-
303 kPa (36-44 psi) for 8.1 models. The spring
pressure inside the fuel pressure regulator
controls the fuel pressure.


3. A fuel system that drops more than 14 kPa (2 psi)
in 10 minutes has a leak in one or more of the
following areas:
• The fuel pump check valve.
• The fuel pump flex pipe.
• The valve or valve seat within the fuel pressure
regulator.
• The fuel injector(s).

4. A fuel system that drops more than 14 kPa (2 psi)
in 10 minutes after being relieved to 69 kPa (10
psi) indicates a leaking fuel pump check valve.
5. Fuel pressure that drops off during acceleration,
cruise or hard cornering may cause a lean
condition. A lean condition can cause a loss of
power, surging or misfire.
8. When the engine is at idle, the manifold pressure
is low (high vacuum). This low pressure (high
vacuum) is applied to the fuel pressure regulator
diaphragm. The low pressure (high vacuum) will
offset the pressure being applied to the fuel
pressure regulator diaphragm by the spring inside
the fuel pressure regulator. When this happens,
the result is lower fuel pressure. The fuel pressure
at idle will vary slightly as the barometric
pressure changes, but the fuel pressure at idle
should always be less than the fuel pressure
noted in step 2 with the engine OFF.

I WOULD however still like to know how to disassemble the fuel cell in order to check the low pressure pump inlet screen. :)
 

Thalasso

Commander
Joined
Jan 18, 2011
Messages
2,876
You cannot buy the low side separately. If the winning has stopped and the pumps are not hot, go boating.
Mine is a 5.0 and specs said that the low side should be around 8. When i put the new one on (low pressure side) it was 17 lbs.
You are correct about the beeping. I had to buy the complete setup.$635.00
 
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