2007 SN196 with ZR6 rough idle/died/won't restart/low voltage

[ScottStewart]

Hello All,
So a couple weeks ago we had four steady days of very heavy rainfall, although my boat had it's cover on, the boat was full of water almost to the floor in the bilge. I pumped out all the water, then once it was dry started the boat. There seemed to be no issues so I shut off the boat and recovered it (currently looking for a new cover). Yesterday I went to head out for a ski and started the boat with no issues, then within about 30 seconds of running it started idling rough and eventually died. I have yet to be able to start the boat. It will turn over fine, barely catch then die. The dash has a digital display of between 10.7 and 11.2 when I am turning it over and the red check engine light is on. The digital display on the dash has a low voltage warning alarm. The analog voltmeter also reads low at all times (starting and with power to dash). Although I know the battery is good, I swapped it out with another one and the issue remains. I wire brushed the terminals as well. If not for the low voltage alarm I would lean towards a fuel issue as it sounds like it isn't getting any as it's turning over. Any help would be greatly appreciated!!!

[CanadaNautiqueGuy]

My ZR6 had that problem last year after a lot of rain. The ECM had gotten wet. Took a while for the service guys to figure it out.

[ScottStewart]

Thanks Canadian Nautique Guy! Did you have to replace the ECM? Any idea on cost?

[a.klos]

I power washed engine a while ago and had similar symptoms and it appeared that my distributor become wet. So check ignition components if they are wet.

[CanadaNautiqueGuy]

Yeah, they did replace the EMC. The part alone was ~ $1,500. Hope that's not your problem.

[ScottStewart]

Just an update so as to help others if this issue arises. It ended up being a large amount of water in the fuel. I had to drain the FCC canister, drain the tank, drain the lines from the FCC to the fuel rails, then pull each spark plug and turn over the engine to blow the water out of each cylinder. Some were dry but a few had a fair amount of water that puffed as mist and water droplets out the spark plug hole. I have 2 gas caps...one on each side of the boat and the one on the portside which I never use was about 3 threads from being closed so I believe with the 4 days straight of rainfall the water was wicking through the tarp and into the tank. Prior to moving on to the fuel issue, I cleaned every electrical connection associated to the ignition system (battery, starter, ground, alternator) which seemed to help my overall voltage, putting it above the low voltage alarm that displayed on the dash. I also inspected all the fuses, relays, ignition/electrical system and the ECM to ensure they were dry as suggested by a.klos and CanadianNautiqueGuy (thanks Guys!) and found everything to be in good working order. Anyway....waisted a day troubleshooting but am back on the water!

Scott