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Super Contributor

Re: Possible ECU problem

Sound like the inlet air heater may not be connected correctly or the relay is stuck on. The relay should be supplied with battery power through a circuit breaker. Make sure the heater and relay are both for the correct voltage.
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Re: Possible ECU problem

Dave10010,  The real problem was isolated when the Port Engine destroyed 2 sets of brand new batteries.  They were both over heated so much that the tops of the top line batteries almost blew the tops off of all the batteries connected to the Port side engine.  When the mechanic disconnected the hot lead to the preheater the problem with the batteries went away.  I understand about the charging reminder you were so kind to send.  We had everything electrical connected to the Port batteries checked, charger, constavolt, altenator all were checked and found to be working fine.  I just have the smoke when I start the Port engine.  Stb'd no smoke no battery issues etc.

 

Thanks for your informative response,

 

Bob

Super Contributor

Re: Possible ECU problem

Sounds like you are trying to chase a problem you don't have. The inlet air heater draws over 100 amps so it's normal for the voltage to be lower during the time the heater is on. It's also normal for the alternator to not charge until the RPM is over 1000 or so. Engine should be programmed to idle at 700 RPM. After engine starts, raise RPM until voltmeter rises, then allow the engine to idle normally. Heater is activated for only 10 minutes or so.
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Possible ECU problem

I have twin 3126-B's (420 HP).  The port engine was destroying new batteries twice.  Had an engineer mechanic come to the boat who claims to have issolated the problem to the pre heating element on the Port engine.  The battery charger and alternator was checked with the alternator being replaced.  This cured the problem with the batteries but on initial start up for the day the Port engine does smoke for less then 30 seconds then dissipates.  The new altenator does not show a charge until the vessel has run above 1,000 RPM.  I'm selling the boat soon but do not want to stick the new owner with a problem I could hide.  However, if it is a costly issue I don't want to replace the part with new but used.  Any suggestions about the problem and how best to address the problem.  This engine has less then 175 hours since new 5 years ago!