2006 Maxum 4200 SY Electronic Throttle/Electrical issue??? New to forum

[legalcollector]

Hi all,

I am new to the forum. I have a 2006 Maxum 4200 SY. I just bought the boat. It was a dealer holdover/no sell until June of 2011. The guy that bought it had financial hardships come upon him and he sold it to me. It has twin Cummins 450HP diesels with electronic throttles. At intermittent times ONLY WHILE THE BOAT IS AT IDLE, the port engine will shut off. I then have to turn off the battery main (under cockpit wetbar sink) then turn it back on and the engine cranks up fine. Its kind of like a hard reset.

Somewhat related to the above (I've got to think) is that the port engine will shift into reverse for 2 or 3 seconds then go back into normal without any operator input!

Both of these issues happen at idle only, intermittently, and I have noticed the port voltmeter fluctuating to a low voltage situation and dances between 10 and 13 on the guage. Is this an adjustment issue, a ground issue, an alternator issue or what?

Any thoughts would be appreciated. Thanks.

Ryan

[pascavone]

i believe the gauges never lie.

you have a short. this is why people sell boats...

The short spike is trippin the other circuits.

diesels and electronic throttles are beyond my ability to make facts up..... but, it sounds like it is your port engine wiring harness.

I would get a mobile marine mechanic to run it down, since you can duplicate the issue consistently.

before you burn something out that expensive.

[legalcollector]

Thank you for your reply. I have it at Monmouth Marine in Shark River, NJ at the moment and they are doing just that. I was hoping to get the "easy" answer from someone who may have had the same issues. Unfortunately with electrical stuff, as you know, gremlins are hard to track down.

Safe waves to you. Thanks.

[shrew]

LegalCollector, Welcome Aboard!!!!

I deleted the duplicate post in the Engines sub-forum since this was the original post. If you're seeing a drop in voltage there is draw somewhere. Is sounds like a ground issue. I would suspect these are related, since they are electronic ignition. Is the boat still under an extended warranty? I would have it checked out anyway.

[rodrigo]

Soounds like you have a bad IAC valve, at least that is what is called on gas engines, I'm sure diesel must have something similar. congratulations on your new boat, I've decided that is my next model after i sell mine...good luck!

[ss3964spd]

People don't sell a 42 foot twin diesel powered crusiers because it has a "short".

Ryan, the fluctuating voltage could be driving the engine control computers nuts. Given the ECU's, and the electronic throttle and gear controls, you'd be smiles ahead by having a qualified Cummings mechanic have a look at it. He'll plug his diagnostics computer into it and likely find the issue - or at least narrow it down to some possibilities. Could be nothing more than that the control units for the engine(s) or throttle need a S/W update.

There is another boating forum that specializes in diesel related issues; http://boatdiesel.com/. Might wanna run your issue past them.

Dan

[legalcollector]

Thanks to all for your input. Dan, I think you're on the right track. The boat is under Cummins Warranty and an extended major components warranty. Its getting checked out, but the certified Cummins tech is reprogramming the software of the electronic controls (the box is mounted port side of the forward firewall) and is checking each connection that could possibly be problematic.

[ss3964spd]

Good deal, Ryan. Not a lot of folks on this forum with diesel powered boats and electronic throttles but please do come back and let us know if the cause was found or the issue resolved.

Regards,

Dan