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melvinke
10-16-2010, 02:30 PM
Tach reading in the 4500 has become very unstable, fluctuating wildly and randomly, and pegs at 3000 for much of the time. The analog tach remains stable and true. I assume that this is more likely to be a faulty sensor (AFS/magneto) than an EFIS problem, and ask whether replacing that would be a logical next step.
Kenneth Melvin
RV-9A, Hillsboro.

AltonD
10-16-2010, 07:41 PM
Mine did the same thing. I tywrapped the wires so they could not flop in the airflow under the cowl where they connected to the harness. Crimped the spade connectors just a little more with neddle nose pliers. Problem has not happened again.

melvinke
10-17-2010, 12:49 PM
You are absolutely correct! Loose spade terminal re-connected properly and the tach reading is as it should be. Many thanks,
Kenneth.