Jim Kaufeld writes:


Anyway, the GEM has an intermittently flaky display. Sometimes it goes crazy
and the bar graphs and digital temp readouts start fluctuating wildly. It
isn't just one engine and it isn't just one cylinder. Its all of them.


I have the EI US8A. When this happened on mine the first time I assumed
it was a bad probe, so I replaced it. Then after about 10 hours it
started doing it again, so clearly it wasn't the probe. Turns out it
was the electrical connection that is midway between the probe and the
firewall. If you simply took the connections apart and reconnected them
the unit would work fine for a few hours then go back to the same
problem. Making sure the connectors have a good electrical contact
solved the problem. I have had my EGT/CHT for about 5 years now and
still have not had a probe go bad.