2003 F115 Problems

On my last outing my motor began losing RPM and acting like it was starving for fuel. It would die down and rev back up until it would finally only run at idle. If I tried to give it more throttle, it would go dead. I got it home, checked the clear filter on the motor and pumped out some fuel to check for water. Everything looked okay. I changed the plugs as they were due. I went out and it ran fine for a few minutes, then started losing power again. The difference this time is when I got back to the dock, I could not turn the engine off. I turned the key, pulled the kill switch, and it would not turn off. I finally put it in neutral and reved it up and backed it down quickly and it died.

I am not sure if these two are related or if I am having some horrible luck. There were no visual or audible alarms or warnings. Any help would be greatly appreciated.

I feel your pain. I have the exact same symptoms. After looking at everything I could think of, I'm taking it in to get diagnosed on the computer. I'm pretty sure mine is an electrical problem of some sort. See F115 running rough from a week and a half ago.

[boats.net]

It sounds like you may have a fuel problem, need to test fuel pressure. You probably have a broken wire inside main harness causing it not to shut off, may need to replace main 10 pin harness.

Thanks for the info. I will take it in to get it checked out tomorrow. I think this is going to be beyond my abilities!!

[jxg]

i was having the low rpms problem, replaced VST filter and plugs and can now get 5800 rpms again, but now boat idles terrible. I have seen a couple of references in different posts regarding 2 procedures, but can't find detailed descriptions on either:

- sync and link (do i need this, i did not touch throttle bodies, just remove intake to get to VST

- adjust TPS (how do i do this)

thanks

[boats.net]

It needs to be put on diagnostic computer to check idle control valve and can adjust TPS at same time.

So I got the diagnostics done and they tell me I have the same problem, plugged VST filter and injectors. This kind of puzzles me because my pressures looked good; there are only 60 hours on this motor; and there are three other filters before the VST filter.

My basic questions are, what can I do to prevent this from happening again? If it does happen again, can I fix it myself? Is it possible to clean the injectors? Is ethenol causing all these problems?

[boats.net]

From what we see in most cases it's from boat not being used for some time, gas going bad and leaving residue in VST. If thats the case then proper storage steps can help to prevent problem.