F225 engine problems

[Polar225]

I have a 2006 F225txr. I bought this boat 5 months ago and have been fixing it up since, and have not been able to find the problem with the motor. When I take it out on the water it starts up right away and works perfect on idle. Once I get out of the channel, I accelerate and the boat will stall at 4000rpm and fluctuate back and forth from 3000rpm to 4000rpm. I took it to the mechanic and the air intake pressure sensor showed up on the computer so we replaced that, still nothing. Then I went ahead and replaced the Low pressure gas pump with an aftermarket one. I took it out the next day and the boat worked great, it was hitting 6400rpm. Didnt go out again for about 2 months while installing GPS and other things and when I took it out, the same thing happened with the motor 3000rpm to 4000rpm My friend suggested for everyone to sit on the front of the boat and I was able to pick up to 5000rpm no more than that. But still even with people in the front the motor will still have the same problems when it wants to. I installed a separate 10 gallon gas tank directly to the motor and the problem still continues so I know it is not from the primer ball to the boats gas tank. It has to be in the motor it self. The mechanic now says that the motor shows symptoms of have been submerged in water because of some hints of green on the plugs in the harness so he says that my problem will be solved by replacing the harness but that is $1000. PLEASE HELP!!!!!!

[dorado42]

Have you checked the VST....it seems that alot of people have VST problems when the boat will not make RPM on the top range. There is a filter in the VST and there is a filter in the VST fuel line referred to as an "F" filter because it is shaped in a "F." I would think if the motor was submerged it would have more problems than "green corrosion." The VST was not terrrible to pull off, just takes some time. I am sure there are a more qualified people that should chime in to help you. I am having a problem with my F225 and several guys have been GREAT in helping me; my problem is different than yours though. GOOD LUCK!!

[rodbolt17]

so now you own a spare intake air pressure sensor.
find a real mokanick.

the laptop did not say the sensor was bad.
the laptop relayed the information it got from the engine ECU.
the engine ECU saw a feedback it did not like.

the laptop is a tool NOT a technician.

place it back on the laptop at the failure RPM AND load and make sure the ECU is happy with all its feedback.
then fix the fuel system.

[madharchod]

i would be checking the fuel injectors as sometimes its not the VST or filter it is the injectors as they tend to catch some carbon and slug from the fuel itself and gets clogged they only cheap to clean ,get them serviced all at one time and see how you go ,you can do it your self but be careful of the pressure line when you remove the injectors

[FabricGATOR]

Injector voltage

What voltage do the injectors trigger at?
12 volt DC, like my car?
SX150TXRY

Thanks.

[rodbolt17]

injector voltage on that motor is present any time the key is on.
the ECU toggles the ground side to operate the injectors.

[Polar225]

i would be checking the fuel injectors as sometimes its not the VST or filter it is the injectors as they tend to catch some carbon and slug from the fuel itself and gets clogged they only cheap to clean ,get them serviced all at one time and see how you go ,you can do it your self but be careful of the pressure line when you remove the injectors

Thank you all for the quick responses. I ended up changing the harness due to that the intake pressure sensor was replace and still would not work. Once I put the new harness and a new intake sensor again, when the motor is on, and you turn it off, you can hear the sensor make a noise like "tac tac tac tac tac". Ran the computer on the motor and nothing comes out now. I went ahead and told my mechanic to clean the fuel system also and he found the filter in the VST tank where the high pressure fuel pump is, almost clogged shut. Also he says there is another sensor near by that opens and closes and that was stuck in the open position due to debris on there too. He also cleaned out the injectors but did not take out the filters inside of the injectors because he said they brake really easy, so he submerged the whole injector in a solution and then blew air into it with the compressor. He said there was also some salt like debris inside the fuel hoses as well and he cleaned those out too. I went to try it out yesterday and the boat hit 6600rpm which I am very happy to see. I was completely stopped and put the throttle down all the way and the boat picked up right away to 4000rpm and started rising steady, like 1000rpm every second or so, until reaching 6000rpm. Does this sound right to you? Isnt it suppose to pick up to higher rpms from the start. I went to try it out for my birthday and there was 10 people on the boat and my maximum is 8. Maybe that had to do since the load on the engine was much heavier. Thank you all again

[rodbolt17]

if the intake air pressure sensor makes noise its broke,.
you may be describing the rattle the ISC valve makes at shutdown while its resetting.
no other sensors on the VST.
if you hit 6600 RPM something else is broke as the rev limiter will grab it at about 6200 RPM.

you really need to find a technician.

[liliepad1]

Doubt your getting 6600 Rpm Rev limiter set 6200 like rodbolt said . Injectors should have been Clean and flowed and new filters installed run's about 20-40 a injector here in fl + time if you don't remove the injectors . Sounds like you found the problem with the Fuel pump filter which happens all the time with out a 10 micron filter installed in the boat . 10 people and 6600 rpm You got a turbo on there . J/k