Port Engine stumble...

[northshoreone]

16v92s running at 1,850 rpm for about 45 min. and the port engine stumbles about 40 or so rpm just out of the blue....it recovered but showed a bit of floating rpm ..by 10 or 15 on the ddec but did return to normal operation. During this I'm checking engine load, fuel pressure etc on both engines and nothing stands out at all. Just found it very strange ....any thoughts out there??

 

[Boatsb]

Electrical.

Dont the DDEC modules use a 12 volt converter? I understand they are very finicky.

I've replaced the converters on them and cummins with the victron isolated ones. The voltage is 100% stable even if the 24 or 32 volt is not.

If memory serves they're less than $150 for the pair.


Although one customer compared price and found the non isolated version cheaper. He almost died bought them before I could explain why they are not the right parts.

 

[northshoreone]

Yes they do run off from 12v. This is a 32v boat and new to me. When it went into the water in June the same engine DDEC had no power. The port genset was worked on and the battery ....which I put in and was new failed so it was replaced at that time...Feb.+/-. The cables were not tightened by the genset tech so no DDEC once tightened no issue. I have personally made sure all battery connections are tight prior to this trip. STILL seems odd to me to be running the main engine power source from the genset battery...but it is an easy place to source 12v

 

[SKYCHENEY]

Can you get the fault codes off of the DDEC?

 

[kelpy]

It most likely is electrical related as Scott said but pull the fault codes, if any, off the display and see what they are in your manuals.

 

[northshoreone]

Yes good thoughts about the fault codes, I don't know why I didn't go there first! I reviewed what was on them when I purchased the boat but have had no reason, until now, to look at them again. I will check that out as soon as I get back on the boat this weekend.

 

[northshoreone]

Back at the boat and a review of the fault codes shows nothing. When picking up oil at WwWilliams the older parts guy said that those engines are known for an occasional sticky injector. I guess for now we go with that and see if it happens again......

 

[johnjen50]

If no fault code could it just have been something in the fuel line that passed through?

 

[SEVEN]

Something in the fuel was my thought to. Maybe a little air? Check the bottom of your racors to see if and bubbles are coming up from the bottom. That happened to me.

 

[northshoreone]

I thought air in the line at first too.... but one would think it would continue to happen and not just go away. But good to check on the racers. They are on my list to rebuild st some point. When I first ran the boat there was a bit of fuel under them on the floor. I tightened up the drain plugs and that seemed to cure that issue. For now...

 

[SEVEN]

I thought air in the line at first too.... but one would think it would continue to happen and not just go away. But good to check on the racers. They are on my list to rebuild st some point. When I first ran the boat there was a bit of fuel under them on the floor. I tightened up the drain plugs and that seemed to cure that issue. For now...

If it’s making its way between the bowl and housing you would not see that. May not be it but it’s easy to replace the o-rings and washers when you replace the filters.