While doing full power tests with our 914, we have found that the manifold
pressure
stops at 30.5 inHg even at full throttle - 5800 rpm. Watching the waste gate
lever from outside the airplane, we observe that the waste gate does not change
position from idle (2000 rpm) to full throttle.
Further, when power is applied to the TCU, the servo motor rotates about 45 deg
towards waste gate closed, then rotates the opposite direction about 90 deg and
then rotates in the original direction about 45 deg. In other words, the waste
gate is not closed at power up with the throttle closed. If I adjust the cable
so the waste gate is closed at power up, it will still attempt to rotate
both ways as before and when it stops, I get a flashing red light. The servo
does
not change position when the throttle is moved from idle to 115%. I have checked
the throttle position with the TLR46 program. By the way, TLR46 says the
servo is at 50%.
All these symptoms are with a new engine on initial run-in. I have double
checked
wiring and connections. Shane at Lockwood thought the servo motor was defective
and I installed the replacement this morning with the same results.
Can anyone make any suggestions or lend some trouble shooting tips?
Thanks
Jim Butcher A185 N241BW
At airport trying to fly!
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