95 SSN not running right

[KaNi]

Today while we were out wakeboarding the boat started running strange. while trying to hold speed at 20 it would bog down...then come back up.....bog down then come back up. I first noticed it at 20mph but after that it happens anytime you keep the throttle in one place. At idle it runs like a champ and in neutral i can throttle up with no hesitation. So I am wondering if this be from bad fuel? That was the only thing that changed since the last time we took the boat out. I tried adding some STP octane boost but it ran the same. If anyone can help me out or point me in the right direction i would appreciate it.

[KaNi]

I'm going with it might be a fuel problem but I'm also going to do the 100hr servicing on it now. Can anyone tell me how to change the tranny fluid in a 95 SS with V-drive? I read through the manual and in the front it shows using a hand pump in the fill/check then further in the manual it shows a plug? Whats the easiest/best way to do it? Thanks

[Sbt3]

The tranny I usually do with a hand pump. The v-drive unit has a plug. I think the recommend 500 hours on the v-drive oil, but I changed mine earlier than that.

[KaNi]

Is it a pain changing the Fluid in the Vdrive? We messed with the tranny today (hand pump) and something wasn't right because we only got about 6 oz of fluid out....going to try something different tomorrow. Do all engines have that water/fuel seperator? I have looked all over the place and cant find one...just an inline filter from the tank. Would the mount it closer to the tank or are they normally mounted on the engine somewhere? I can't wait til I have boats figured out :???: Thanks for the input sbt3

[kogston]

You might want to check the oil pressure switch, as it is designed to limit RPM if oil pressure is low, or if the switch goes bad. If I remember correctly, there is 1 wire that connects to the switch, and if you disconnect it and everything runs fine, that tells you it is the switch. before and while you do this, be sure your oil pressure looks good on your dash. It uses a separate sensor for the display.

[MHayes]

I sounds like the boat my be in limp mode based on what you said. If it was bad fuel, you would be able to notice it whether it's in gear or in neutral. Several things can throw it into limp mode, so more than likely you'll need to take it into the dealer to get it diagnosed.

[KaNi]

I havent heard "limp mode" before...Whats that? It's hard to explain what was happening because it wasnt a really noticeable bog down...you could just feel it and hear it. The speed didnt get affect much if any. I dont know how to explain it. I can't take it to a dealership though so I'm going to have to figure it out...plus I'd like to learn more about boats. Should I check everything in the ignition system too? I changed the plugs, oil, in-line filter, and I'm working on the tranny fluid. The engine doesn't have a fuel/water seperator on it..that I can find at least. What else should I check? Any help would be GREAT!

[coloradonautique]

I would be really surprised if it did not have a Fuel/Water seperator canister. What engine do you have in the boat? GT-40 EFI or carb?

Do a search on limp-mode and you should find some good threads. It happens when the engine computer senses something is amiss, usually when over temp or low oil pressure.

You should also download the service manual (downloads section) for your engine and read the troubleshooting section. That will start you down the path of finding the source of your problem and also get you more familiar with the boat & engine.

Good luck,

Lorin

[KaNi]

It is a GT40 EFI. I haven't had any luck finding the canister so I'm guessing there isnt one. And will down load the manual and see what I can figure out. Thanks!

[coloradonautique]

GT40 EFI definitely has a FCC (Fuel Control Canister) somewhere. It is definitely needed for the EFI engine to prevent vapor lock among other things.

Can anyone else confirm and locate where the FCC is on their SSN?

[KaNi]

Well.....I changed out the in-line filter comming from the tank. After the filter the next place it went was the low pressure fuel pump. And right above that was the high pressure fuel pump. I almost pulled the low pressure pump of b/c it looks like a canister on the bottom of it! Afer the high press it looks like it goes straight to the injectors. I'm going to be working on it tomorrow and possibly taking it out to see how its running. I also looked up that "limp mode" and don't think thats whats hapening based on what I read. It's not bogging completly down....just hesitating or something when its at speed. I don't think it was holding my RPM's down either. Anybody on PN use Seafoam? Somebody reccomended it for water in the fuel so I mgiht pick me some up. Thanks again