2016 Navion 524V Diesel Generator.


My diesel generator would start and operate properly.  When the remote panel stop button was pressed the generator did not shut down.  The only way to stop the engine was to use the stop lever.  I contacted Cummings for assistance and their trouble shooting information had no information of this condition.

When the generator starts, power is applied to the fuel pump and the fuel solenoid.  The fuel solenoid piston opens the fuel line such that fuel can flow into the engine. 

When the remote stop button is pressed, a signal is sent to remove the power from the fuel solenoid, allowing the fuel flow to be stopped and the engine will stop from lack of fuel.

The stop/run button in the generator compartment is a two circuit switch, one for the fuel pump and one for the fuel solenoid.  When this button is used in theory the engine will not start nor run.

When I used the stop/run button the generator continued to run.  In fact with the button off the generator would start and run.  This eliminated the remote panel, wiring and the generator control panel as the source of the problem.

I disassembled the fuel solenoid and found the piston was “stuck” such that the fuel would flow into the engine.

I was able to remove the piston, reassembled the solenoid and reinstalled.  The piston moved freely during the reassembly. 

The engine started and shut down for one cycle, then, the problem returned.

I removed the fuel solenoid again, found the piston “stuck”.  The second time before reassembling, I made sure there were no burs on the piston.  Additionally, I “stretched the piston return spring a little to give it a little more “push”.

The engine was started and shutdown successfully for several cycles.  I called Cummings and updated them on what I had found so they could add to their knowledge base.

Hopefully, no one with a diesel generator will have this happen, but in case, I hope the above is useful.