DF 150 Hi rev alarm

[cprice1]

Had a high rev alarm at 4100 RPM, the flickering tack alarm light won't go off even after killing the engine and turning the key back on. Also on the same engine after getting to shore, the fuel pump continued to run even with the key off.

A day later the fuel pump stops with the key. High rev alarm still on.

Both engines run fine.

Any ideas?

What gives the ECM a engine speed input?

[Hoosmatroos]

All other lights are off?

Lets say you overrev'd the engine on purpose (you trimmed up to far and the propeller surfaced) and caused the engine to over rev, the engines computer immediately limits your rpms to 3k and flashes the rev limit light. To reset the rev limiter, if it was working properly, is throttle all the way down to idle speeds and the rev limit would self reset, the rev limit light would go off and you would have full power again. But you have to bring the throttle back. Now what the engine computer looks for, how it is checking to see if you did bring the throttle back to idle, is the throttle position sensor (TPS). The throttle position sensor is how the engines computer knows how much throttle you are trying to give the engine.

If the TPS is bad/something wrong with it, you would also get an overall lack of power. As the engines computer does not know how much throttle you are giving the engine.

So check the wiring and TPS. Perhaps swap the sensor with the other engine. I think there is also a TPS initialization but that I'm not sure of.

[Harper]

With your description of the over rev light "flickering", coupled with the engines still "running fine" with no indication that the ECM is putting the engine into fail-safe or limp mode, it sounds like it could be a short in the wiring in the alarm system, somewhere in the cabling between the motor(s) and the dashboard.

[cprice1]

DF 150 HI rev

Thanks, I will check.


Turned out the Tachometer was bad.