Engineer rumbles on

[Jerry De Santis]

P337G N34EC
GOt a problem: on front engine when mixture in is at cut-off to stop engine it keep rumbling on. To stop engine I have to shut master off. Any ideals out there what the problem might be?

Thanks!

[GAdams]

It’s likely the cable which connects the in cockpit mixture control and the fuel on the engine has either stretched beyond the cutoff limit or the attach point of the cable has come loose or out of adjustment. Could be something else but I would start there. Or it Could be the engine is just as stubborn as it’s owner. To turn it off you’ll have to shoot it.

[Jerry De Santis]

Thanks for the feed back. Should find out today if we need to investigate the cable in more detail. The FBO working on it didn't think it is the problem. They are almost as stubborn as the owner.

[SteveG]

The position of the master switch should have no bearing on whether the engine runs or not. Or did you mean that you are turning the ignition switch off to stop the engine? If the master switch kills the engine ignition you have a second problem to solve as well as the fuel cut-off issue.

[Jerry De Santis]

Turning ignition switch off to kill engine.

[Dan schultz]

Jerry

If the electric boost pump is off, pulling the mixture provides complete fuel cutoff.
If the motor continues to diesel, I suspect the problem is internal to the engine driven fuel pump.

Dan
N67S

[Jerry De Santis]

Turned out to be the engine driven fuel pump. Initially the FBO sent it in for repair and the repair station sent it back saying nothing wrong with it. Problem continued. The FBO decided to take fuel pump off of rear engine and install on front engine. Problem gone. Original fuel pump being sent back out for repair. Will keep you informed of result and repair station.