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Frank

Monsoon acting like an old lady

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Frank

I have a late 90's model Sporty with an EFI Monsoon that is starting to act up. After it warms up performance drops way off and almost can't get out of it's own way. Almost seems as if it is running out of fuel. This spring, if that is what you can call it, I replaced the high pressure fuel filter, dist. cap, rotor, plugs, and oil. Every thing else same as previous years. Engine only has 240 hours or so. Seems to run fine and get plenty of fuel before it gets up to temp. I didn't have a fuel pressure gauge with me but will take one next time I go to the lake. Any ideas??? Does anyone have a schematic for the fuel injection system, monitoring points, etc. Any thoughts would be appreciated.

Regards,

Frank

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SmoothWaterMan

What is the exact year of the boat, and are you sure it's temperature related? Can you see a constant point that it changes performance?

Peter

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Poemoroe

Maybe your water pump or impellar is bad. I was told that once the engine reaches ~203deg it shuts down to around 2000rpm only. (Limp Mode?)

Have you checked your impellar?

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Frank

I replaced the raw water pump this spring as well. Gauge is reading 160+/- like it always has. I believe the boat is a 97/98. I am not certain the the engine has a temp fail safe other than the plastic plugs in the exhaust manifolds. Can anybody confirm this? Discount Inboard Marine sells an ECM temp sender, http://www.skidim.com/prodinfo.asp?number=R020019 , which I am thinking my be the cause of the problem. Can anyone provide some insight on testing parameters?

Frank

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SmoothWaterMan

Frank,

At what point does it start to "not get out of it's own way" ?

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Frank

I have been out twice this year. Both times 10-15 minutes into use. Both times I have had small kids on the boom and taking it fairly easy. When it's time for the big kids, SOL.

Frank

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RTS

Fuel pump filter clogged, on the fritz? Any idea when it was last replaced?

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martho

How do you not know what year your boat is?

Give us a bit more description as to what is happening...

Does this resolve itself after a shut down and restart?

Does this issue resolve itself over time, or once it starts it stays that way?

Fuel filter is a good suggestion, too.

Edited by martho

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gooddog

Did you check the hoses for debris from the last impeller? If its clogged with pieces of the old impeller it may not get enough flow to cool.

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Frank

I will check the raw water impeller for damage. The one that was removed was still usable. I replace them every other year, every 50 hours or so. I can replace the thermostat as well but the temp gauge is not indicating anything unusual. I never can remember the year of the boat but you can verify by the vin number on the transom. The boat is kept at the lake and I don't anticipate to get there until the weekend. I plan on taking a fuel pressure gauge with me to verify the fuel pump status. If the engine is running lean, which I anticipate, it's either doing it because the fuel system can not deliver or the fuel injection controls are telling it to reduce flow. Any thoughts.

Frank

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electricjohn

Be VERY careful when taking fuel pressure readings, especially if engine is hot. EFI pressures can get up to 50 psi. And let the engine room vent for a while when done. Never used a F.P. gauge yet, and don't know if the connection is leak proof. Anybody??

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LS-One
Did you check the hoses for debris from the last impeller? If its clogged with pieces of the old impeller it may not get enough flow to cool.

Plus1.gif

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SacRiverRat

Could it be a bad temp sensor for the engine computer... do these engines have a open loop / closed loop modes. Could the engine be thinking that it is still in "warm up" mode, when it is really up to temp, and therefore applying too much fuel in the mix etc..?

Not sure on your engine, but often there are two temp sensors.. one for the gauge and one for the computer

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05lxi

Here's a suggestion you might try. Send your computer chip to have it recalibrated. I have had simliar problems with the chip telling the injectors when to spray. I had chip recalibrated and It stopped. I have also seen a dieseling effect, and exsessive gas smell and fuel efficiency due to this problem. It's also cheap, take out yourself bring to dealer or send to Malibu. Dealer might charge you a little, but if you send to Malibu it's free just pay for shipping to and from your house. Good luck

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Frank

Finally made it out to the lake today with a fuel pressure gauge and confirmed the fuel pump is not keeping up. At idle and while in neutral she maintains 40psi or so but under load it drops to 20 at 15/1800 rpm and above that drops to 10 psi and the engine starts to run out. Any recommendations on a pump source?

Frank

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electricjohn

I would also check the fuel filter and fuel pressure regulator. The pumps are pretty dependable.

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RTS
Finally made it out to the lake today with a fuel pressure gauge and confirmed the fuel pump is not keeping up. At idle and while in neutral she maintains 40psi or so but under load it drops to 20 at 15/1800 rpm and above that drops to 10 psi and the engine starts to run out. Any recommendations on a pump source?

Frank

Skidim.com has them...they run about $350.00. Not super hard to replace yourself.

Fuel Pump at Skidim

Edited by rts

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pup

Before you throw 350 bucks at it make sure it doesn't have a filter at the tank. You could also run the engine out of a 5 gallon fuel jug. Isolate the engine from the boat. Run a hose from a jug to the fuel pump inlet. Your problem screams plugged fuel filter.

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Frank

Thanks for the input.

I opened up the floor to look for a inline filter, before the pump and could not find one. Accessed the fuel line from the pump to the backside of the fuel tank. The only other place it could be is on the top of the tank. On the sporty there is and access panel on the top of the transom where the shut off valve is located which I will open up next time I am out. Any one experienced where this mistery filter might be? I can try the alternate fuel tank idea easy enough, just leave the return fuel line connected to the main tank.

I am not certain how to test the fuel pressure regulator. Any ideas?

Regards,

Frank

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electricjohn

Frank,

Not familiar with the sporty, but on my '03 the filter was inline about 6" from the tank. Recently relocated it to under the floor because it was a pain to get to where it was. The fuel pressure regulator relieves fuel pressure from your fuel rail when no engine vacuum (ie: engine not running) is produced and regulates it @ 40psi when there is vacuum. It is mounted on the fuel rail and the return fuel line comes off it. Never seen one fail, so go for that filter.

Edited by electricjohn

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Baddog
Thanks for the input.

I opened up the floor to look for a inline filter, before the pump and could not find one. Accessed the fuel line from the pump to the backside of the fuel tank. The only other place it could be is on the top of the tank. On the sporty there is and access panel on the top of the transom where the shut off valve is located which I will open up next time I am out. Any one experienced where this mistery filter might be? I can try the alternate fuel tank idea easy enough, just leave the return fuel line connected to the main tank.

I am not certain how to test the fuel pressure regulator. Any ideas?

Regards,

Frank

IF yours is anything like mine, the mystery fuel filter will be found on top of the tank but under the carpeted panel on top of the tank. EJohn is right, it is a PITA to get to and moving it into the bilge area is good project I should do someday.

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Frank

I will try to take some pictures this weekend. The sporty is pretty simple. Only carpet is on the floor and glued to the gunnels. Rear seat base just sits on the floor and the back is screwed to the fiberglass. No storage behind the rear seat as the fuel tank is full width of the boat and almost as tall as the boat is deep. Centered in the back on the top deck is the fan louver and a small access to the fuel shut off valve. My last thought is that if the mystery fuel filter exists, it will be located under the louvered cover. Again I will investigate this weekend.

I have no idea why they put a fuel shut off valve on the tank. Someone told me once that it was incase of a fire, so you could turn off the fuel. In my opinion, if the boat catches on fire and I can't control it with the fire extinguisher, it’s time to abandon ship!

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RTS

Mine has no fuel shut off valve. I've seen pictures of other Sunsetters, and they have an access port in the rear storage compartment with a label leading you to the valve, but mine does not. No access port, no shut off valve. And I've accessed the fuel tank area to change the filter and the fuel sending unit.

Mine must have been built on a Friday afternoon.

And I would not be looking around for the shut off valve in case of fire either...I'd be in the lake, swimming fast, trying to remember the number to State Farm.

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VinRLX

I believe they stopped installing the shut off valve around 2002-2003. My boat does not have one. Not sure about the fire thing, but they used to shut the valve off at winterization, IIRC.

If you do have a filter back there, you may be able to access it through the fan louver. If not, remove the seat back. That is a pita, do a search here if you've never done it.

Any other Sporty owners have a filter back there???

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wienrdog

Not sure on the sporty, but some have mentioned a screen 'filter' on the pickup in the tank that can get partially blocked with debris. You'd have to pull the pick-up and see if it has any plastic stuff clinging to a screen. It could be restricting the flow enough so even a good fuel pump and outside filter can't keep up with the engine.

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