16v92 Ddec 2 on 65 Hatteras power loss

[Wcampan676]

My starboard engine all of a sudden won’t go over 800 rpm in gear. When in neutral it slowly responds up in Rpm. Very slow power loss. Do these Ddec have a safe mode. Any help. Check engine lite on code 46 probably cause battery charger went bad 2 months ago and code 55

[Captain Ralph]

I am assuming you only have starting batteries and not a set for the DDEC computer.
During starting the volts are going way down and the computer is crashing.
IMO; Engine is starting in stupid mode.

[Wcampan676]

I have house batteries 2 port 2 and starboard 2. 3 banks. Recently about 8 weeks ago there was a battery charger issue. Starboard batteries were dead. I replace mastervolt charger all good I’m assuming that 46 code was from that. All batteries are good. How do I get out of stupid mode.

[kelpy]

DDEC engines do not have a limp mode. Low initial DDEC voltage will just cause a non-start condition. They start or they don't. Low DDEC voltage while running will initiate an alarm on the displays. If the voltage continues to decline while running, the computer will eventually cease controlling the engine and it will stop.
The engines do have a comprehensive readout on the displays to show basic alarms and system faults. If that doesn't show the fault(s), you need to get a tech down to hook up his computer to the engine computer to run a full diagnostic and find out what is wrong. You should have the DDEC troubleshooting set of books on board.

[kelpy]

Make sure that both ECUs have the power plugs securely attached. Check the voltage at each one. On my 16-92s , the lower ECU controls the engine and the upper ECU essentially just provides the drivers for the forward 1/2 engine injectors. Unfortunately, the displays don’t show each 1/2 engine voltage. The diagnostic computer will.

It may not be coming out of warm up/ smoke reduction mode which leaves it in 1/2 engine. Or one air shut off flap is tripped. Try the easy stuff first. I have had both conditions occur over the years.

I would check in my DDEC troubleshooting books to help with your engine condition but it will be awhile before I can get to the boat again.

And thanks for your constructive comment there Ralph. I would imagine that you will be hearing from a Mod soon.

And while I’m here, I have a new in box 32 VDC Reverso pump if anyone needs one. PM me and I’ll send a pic. $200. I’m in Fort Lauderdale and prefer not to ship.

Link to Dropbox pics. https://www.dropbox.com/sh/coqppc89s...Hdr3xvsGa?dl=0

Pump Sold.

[Hat52MY]

Check the fuel pressure (40+ psi) on the DDEC to ensure the engine is getting fuel and you don’t have a clogged fuel line or filter. Had the direction indicator for the filter out of alignment on the Racor 1000, restricting fuel flow, and the engine RPM drastically reduced under load. Once I put the directional value back in its proper orientation, full power/rpm resumed.