Engine RPM

[RobS]

No computer controls, this is a mechanical engine. The governer is mechanical and controls the fuel delivery.

[furball]

So let's say the two issues are not related. Just looking at thruster load causing drop in rpm. Pumps are not electric, no ECM. After some more research, it doesn't appear that electrical load changes load on the motor. The alternator like the water pump creates a constant load on the engine at idle regardless of draw. So what is effected by electric load on the system, injectors, anything else?

[RobS]

Injectors are mechanical, the new common rail are electrically actuated. I would hook up an outboard tank with a squeeze ball direct to the banjo bolt fitting on the on-engine filter assembly. If she fluctuates idle speed squeeze the bulb and see if there is any effect. This will at least isolate your fuel system as the culprit. Next step might then be to have the pump pulled and sent out to a pump shop.

[furball]

Rob, I agree.
I will isolate the fuel next trip provided I can duplicate the issue or issues.
Found out today that alternator does change load on the engine as it creates more amp output. It' really interesting how many different opinions and ideas I get when I talk to different people. All of whom I think know their stuff. Hearing a lot about diesel quality because tankers often load diesel after unleaded and ethanol may be causing some new contamination problems.
So far, most likely culprit is still the governor in the fuel pump. My best source on diesel engine issues seems to think its a pump issue, but checking amp draw on the thruster and leak/obstruction in the fuel system need to be ruled out before pulling the pump. Thanks to everyone for the education. Interesting stuff