2006 Four Winns Funship 224 Volvo Penta 5.0 GXI Takes Long to Get Full Power & RPM

4Winns4Fun2

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2006 Four Winns Funship 224 Volvo Penta 5.0 GXI Takes Long to Get Full Power & RPM

Hi All - first post here. Have had this boat about 4 years now. It had about 60 hours when we got it. It's now at about 140 hours. I have annual maintenance (oil changes/drive inspection/winterization) done by the same place I bought it from. It's been trouble free until a couple weeks ago when I noticed it did not want to go past around 2200 rpm when I first took it out. It felt weak on power naturally.

I always warm up the engine for several minutes before going out and I always ease into the throttle, but this time as I was easing into it, I could push it further and further and it would just stay at the same ~2200 rpm and not pick up speed. Over the next few minutes, it would slowly increase engine speed and water speed until it suddenly felt like it regained all the power it should have and would build rpms again as expected.

It's repeatedly done this every time I've taken the boat out since (maybe 5 or 6 times now).

I know car engines very well (have built them from the ground up), but I'm not well versed on boats outside of the engine itself - as it's just a car engine with some small differences.

So, I started with the basic fuel filter change first. I've taken the boat out once since and didn't really notice any difference. I poured the fuel out of the old filter and didn't notice any obvious debris or water. I nearly always fill up on the water with premium (non-ethanol) gas, but I have put a few gallons of auto pump gas (with ethanol) into it a few times in the past when I didn't have enough to make it to the pump on the water.

I'd love to hook-up a scan tool and see if the ECU is storing any codes, but have no idea what tools are out there for this engine. There's no OBD-II port of course and not sure if there's a diagnostic connector at all on this engine. A few connectors look like possible candidates. I've found some scan tools, but they are specific to different vintages of MEFI and I don't even know what version this engine is... Volvo Penta couldn't even tell me after a phone call.

Bottom line, I'm looking for some feedback before I start throwing parts at it. Plugs, cap/rotor, wires would be my next steps without knowing any better. Appreciate some insight. Thanks.
 

alldodge

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Howdy

Rinda is the point of contact for scanners and software (Diacom)
http://www.rinda.com/marine/marinemenu.htm

The first thought of low power is either a code or low fuel pressure. Your pressure at the rail should be around 60 psi. Can get a loner gauge at many auto parts stores
 

4Winns4Fun2

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Thanks. I've been thinking it may be fuel related. Maybe the pump is on the way out, but just guessing at this point. I have a fuel pressure tester at home so as long as there's a service port somewhere on the engine I should be able to use it.

Any idea what version of ECU I have on this boat? e.g., MEFI 4
 

Shaper79

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Look up "man cave mechanic " utube on the fuel cell and how to test. If fuel checks out. Then need to test the spark power.
 

alldodge

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Don't know which MEFI, but its either a 3 or 4. So far as operation the 3 and 4 are the same for your motor, could look on the back for info. The 4 allows for boost control (blowers) which your not using. Most probable its a 3 because they were used most before going to the 555
 

4Winns4Fun2

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Thanks guys. Found the mancave mechanic video. Engine looks just like mine and I have the same fuel tester he used.

Any idea where the ECU diagnostic ports are located on these engines? It's not obvious to me after looking.

As for MEFI version, I grabbed all the numbers I could off the ECU and it still didn't help Volvo. Seems like it should be much easier to determine which version of the EFI I have. I've been trying to sync up with a service manager at a local Volvo Penta dealer to see if he can help.

Any feedback on this scan tool by the way? https://www.obd2allinone.com/mefiscan.asp $200 is justifiable in my mind

Thanks again.
 

Thalasso

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Thanks guys. Found the mancave mechanic video. Engine looks just like mine and I have the same fuel tester he used.

Any idea where the ECU diagnostic ports are located on these engines? It's not obvious to me after looking.

As for MEFI version, I grabbed all the numbers I could off the ECU and it still didn't help Volvo. Seems like it should be much easier to determine which version of the EFI I have. I've been trying to sync up with a service manager at a local Volvo Penta dealer to see if he can help.

Any feedback on this scan tool by the way? https://www.obd2allinone.com/mefiscan.asp $200 is justifiable in my mind

Thanks again.

Look on the left side top of manifold. Next to the throttle body. There should be two of them. One white one gray
 

4Winns4Fun2

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Fuel system checks out. Saw about 18 psi on the low side and about 50 psi on the high side and that stays constant when revving the engine. FP regulator was clean as well. What next - plugs?
 

alldodge

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Being at 50 instead of 60 psi then this is low. Also need to see what the pressure is when trying to get on plane. Revving the motor does not give a true view of the pump performance
 

4Winns4Fun2

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I figured someone would chime in regarding FP.... agree, I should load the engine and watch FP but that's a bit tricky as the gauge cannot be viewed with the engine compartment closed. Short of sticking one of my kids down there I'll have to think about how to best tackle this. Maybe just leave the compartment open for a bit.

And I thought 50-60 psi was considered normal?
 

alldodge

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And I thought 50-60 psi was considered normal?

Every posting of the GXI is 60 psi for VP. Not an expert with VP but with all the threads involved with they all come back to the same number. Merc uses 30 to 45 and the same pump type
 

alldodge

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Never did say which Gxi you have but the guy might be right and I may have misunderstood Fun Times , wouldn't be the first time :facepalm: but found this, so it depends if yours is a B/C/D or E

Gi Gxi Osi Osxi.jpg
 

4Winns4Fun2

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Just wanted to follow-up and let everyone know that I decided to go ahead with a tune up. Pulled the plugs - looked OK aside from a couple running on the rich side, pulled disty cap and man were the terminals corroded to heck. Pretty sure the cap was the issue. New cap, rotor, plugs and wires and it runs like a top again.
 
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