05 HPDI shutting off on plane!

[Teamsibley]

If anyone could help that would be great!! I purchased an 05 HPDI that has low hours on it. What it is doing ( soon after purchased) is the engine is completely shutting off. You can idle all day with it. But after you get on it for a while it will almost seem like the key is being turned off then back on while running it. I have had all the filters cleaned and replaced. Had the gas drained and replaced. Replaced everything from the tank to the engine regarding fuel lines and it still does it. I brought it to the boat shop and they said it was the mid pressure fuel pump. They came to this diagnosis after having the laptop hooked up and running YDS. Purchased the mid pressure fuel pump and that hasn't fixed it. Now they are saying that it has to be the relay to the mid pressure pump and if it's not that then it has to be the ECM!! I have been told that those never have issues. Please help!

[LaCajuninNC]

Have you replaced the high pressure fuel canister, above the VST tank, the small silver one? If not that could very well be your problem.

[Charlie206]

Any part can have issues. I agree it's one of those most likely. A real mechanic would determine which one. Any boat owner can guess at it and wind up replacing all 3. Why pay a mechanic to do the same? It is not that unusual for a relay to act up.

[geobass]

It might be simple. I have an 04 and it was the battery connection. Could idle but run and it a wave and off it would go. A couple of time as soon as it would shut down it would start right back up without even hitting the key. Just something to check out. Hope if is that simple for you as it was for me.

[Teamsibley]

Thank you for your input. Looks like we will find out soon. It acts exactly like a loose battery connection but unfortunately that's not it. I have replaced the small canister as well with no luck. Once it gets resolved I'll be sure to pass along what the actual issue was. Thanks again!

[Petersdp]

Did you end up finding out what was wrong I'm having the same issues with a 2006 250 hpdi

[JoeFriday]

Are you running your battery connection to the main posts or screw on posts? Don at European Marine did a long post about battery problems with the screw on posts. The synopsis was that internal to the battery, the screw on posts are not connected the same way as the main posts. There are converters (I got a set at OReilly) to run the connections off the main terminals and not the smaller screw terminals. When I read what you described, my first thought was electrical then I remembered Don's post about this.

[Petersdp]

I guess I will try that cause yes I'm running them off the screws

[X19Indy]

I had a fuel line that would collapse when under pressure. Might check to make sure your fule line isn't kinked, pinched, or broken down on the inside.