jetfreak

My Feedback: (9)

For those who have been running Jetcat turbines and feel capable of making an educated guess at the reason I may have gotten this fuel failure. I have posted the last 8 seconds of the turbine before it shut down. The readings from what I can tell do not look like an "leak/bubble" type of fuel failure.

Thanks
Sean




http://www.rcuniverse.com/forum/m_8131899/tm.htm

KC36330

by the EGT and pump voltage you lost fuel flow to the turbine, could be the solenoid closed for some reason, the fuel pump got some trash in it that stopped flow for a second as it jambed the gears (I've had this happen before), the list goes on and on............

seanreit

My Feedback: (60)

Your pump voltage goes up indicating that it was having a problem achieving RPM setpoint. I would suggest that this was a restriction of some sort.

erbroens

Matt is the man to answer this.. meanwhile my educated guess is a fuel obstruction.


You may check the copper tubes wich usually are they that hold any residue wich can cause the fail, the fuel filter, a faulty solenoid or a too
loose connector on the ECU, a defective fuel pump, just to name a few causes that can cause this.

Shok

My Feedback: (28)

We had a P-60 do something similar, turned out to be some gunk in a filter

Be sure after you clean your lines and check everything to do a manual reset.
Sometimes after things like this, the motor will not achieve high rpm anymore and you need to reset by going to full throttle with the manual button held down.

Wayne22

My Feedback: (2)

So, between 6.8 and 7 seconds when the rpm dropped, you did not throttle back, is that correct?

seanreit

My Feedback: (60)

Wayne, the pump voltage would have dropped if the throttle was brought back, instead the pump voltage is rising indicating obstruction, or higher throttle position.

lov2flyrc

My Feedback: (24)

Sucked air.....

jetfreak

My Feedback: (9)

Nah... pulse width on the ecu shows to be at 78 all the way through the entire 8 seconds. I will double check when I get home tonight but pretty sure on that one. I know that when I heard it quit... I naturally asked for more throttle but I don't think the ECU is gonna show that.


Thanks
Sean

Wayne22

My Feedback: (2)

Thats where I was leading to Sean... you would expect a pump voltage drop with rpm drop, but instead it went up...I'd say fuel line restriction.....

jetfreak

My Feedback: (9)

From reading the manual and not seeing what JETCAT is saying about sucking air is what leads me to believe that it did not suck air. how much is rapidly from my logs we see a .2 increase in voltage.....before it quit.
Engine quits with a
trail of white
smoke.
Low RPM or Fuel
Fail
Code 7
99 times out of 100 times this is caused by air in the fuel
system. Make sure there is no leaks in the fuel system and
most importantly, get all the air out of the fuel filter. The fuel
filter should not be hard fixed to the plane but allowed to hang
free. It is best mounted vertically. When you purge the fuel
system, tap the filters while the pump is running to get all the air
out them.
You will see the pump voltage rising rapidly before it shuts off
because the ECU is trying to maintain the RPM. The
temperature and RPM will be decreasing. The ECU will turn off
the pump when the RPM is approximately less than 24,000
RPM.

seanreit

My Feedback: (60)

Keep in mind, if you had an obstruction that emtied the uat, but that obstruction caused negative pressure in the uat via the pump, the uat could have siphoned fuel through the obstruction while you were deadsticked, showing a full uat, but that there is really an obstruction.

Firing up the engine and running to full for a minute should repeat the problem if this is the case.

lov2flyrc

My Feedback: (24)

Sorry...should have paid more attention... reading your description, I saw "white plume smoke" along with the climbing Pump PW... Did not catch the "I did not see" before it...
I would agree...sounds like a fuel supply issue...