J.P. Instruments EDM 740 Pilots Guide - Manual (Page 34)

Page 34 Engine Data Management
Display Symptom Probable Cause Recommended
Action
EGT and CHT
not uniform Dirty fuel injectors or
fouled plugs. Check injectors and
plugs. Non-uniformity
is normal for
carbureted engines
Decrease in
EGT for all
cylinders Decrease in airflow
into the induction
system. Carb or
induction ice.
Engine units set to
Celsius
Check for change in
manifold pressure.
Check that the alarm
limits are set to
Celsius degrees
Slow rise in
EGT. Low CHT Burned exhaust
valve. CHT is low due
to low power output. Have compression
checked.
High CHT on
cylinders on one
side of engine Obstruction under
cowling. Check for improper
installed baffling, cowl
flap misalignment or
bird nests.
Rapid rise in
EGT/CHT of one
cylinder Detonation. Reduce power.
Sudden off scale
rise for any or all
cylinders
Pre-ignition,
or Normalize view,
or failed probe.
Full rich and reduce
power,
Change to
Percentage view,
Check probe.