Engine stoppage/ Momentary Ignition interuption

We have a 2003 Sundancer 340 with twin 8.1 horizon 8.1 inboards. Since memorial day 2010 we have been struggling with port engine ignition issues. The repair tech last diagnosed the problem as crank sensor and fuel pump relay related and both were replaced. A week ago we cruised to Kelly's Island for dinner with friends on the boat (6 sat. miles). The boat ran great going over. On the return trip the starboard engine quite 8 to 9 times and had to be restarted. Each time, the engine quite, the E-80, RD 424 & DSM300 lost power for an instant and then immediately came back on. However, the engine never restarted and needed to be manually restarted.

The repair techs came out yesterday and drove the boat for 4 hours without a miss????????

Intermittent problems are difficult to diagnose. It sounds futile but have a look around... wiggle the wiring that you can access while its running. I had a 2003 240 DA that did that exact thing. It turned out to be the main power feed to the (nearly unreachable) fuse panel under the helm. There was a 'through panel' terminal (post on each side of the fuse box) and on the inside and there was no nut on the main feed connector. It wasn't in the box either so this boat had been like that since new... cuz' it only had 40 hours on it when I got it.

As John said, Intermittent issues can be a pain. Good techs want to find the issue too. And we all know it never happens when the mechanic is there!

The fact that you also lost several main systems at the same time should be a major clue. I would bet that those systems are all powered from the same battery bank as the engine that is failing. That would lead me to want to very closely inspect all main power and ground connections on that bank, the solenoid, and the solenoid trigger paths, breakers, etc.

Same year boat, same symptoms... hmmm... kinda' makes ya' wonder.
It's what mine did; good most of the time... it would stumble a bit on occasion... then sometimes it would die but fire right back up. I just happen to catch it by wiggling / moving the harness around one day while the boat was running. It did the little stumble on me so I dug in and sure enough... there was the problem. It was really hard to get at (and see) but I managed.
I'm not sure how the wiring is on the twin power in an '03 but find the feed to the fuse panel that powers up that engine and inspect it closely. For fun check to see that the nut I was talking about is on there. If it is carry on with chumbleys list of checks.
What are the odds its the same thing? That'd be something... :wow:

I was thinking... if it is the same thing we should put out an APB;
EVERYONE,
CHECK YOUR NUTS! :lol:

magster65 said:

I was thinking... if it is the same thing we should put out an APB;
EVERYONE,
CHECK YOUR NUTS! :lol:

Click to expand...

Just checked mine, I have two:smt038

Is there any information, guidelines, or protocols out regarding how to handle and maneuver a Sea Ray Sundancer 340 with twin inboard engines if one engine stops running?

I am having a similar intermittent loss of power. I will drop the stbd engine for a split second, the smartcraft beeps, all the gauges drop out and then come back and power is restored, all within the span of less than one second. On inspection I found the 90A fusible link on the stbd starter was burnt. I also found the main 50A breaker on top of the motor was very spongy and did not positively snap closed. Further I found the starter fuse and relay were abnormally hot. This was the case on the port motor too, though the main breaker and fusible link on port appeared normal. I am wondering if I have a fuel pump problem developing in both motors and the combination of resistance and bad main breaker on stbd are causing the momentary voltage drop out. I am also having intermittent disconnection of SeaTalk network causing my slave E120 to loose connection with the master. All of the instrumentation on the bridge hangs on the stbd battery bank. Seems like a logical pattern. Anyone else having similar issues?

Yes. What was the Fix? I loose power momentarily on my port engine and resets smart craft and gauges. Does it at idle and underway.

I have this exact problem on my 1999 270 with the 7.4 mpi!! Replaced the ignition switch, coil, cap and rotor, fuel/water separator. Ordered plug wires a few days ago. I also cleaned and tightened grounds, bought a new starting battery(was old and the previous owner thought deep cycle is a starting battery...sigh). Alternator was tested and Jager only putting out 11.3 volts. New one has been ordered! Any other ideas? I am at a loss, soo is my bank account lol