J.P. Instruments EDM-700 User Manual

For Your Safe Flight Page 25
Engine Diagnosis Chart
The following chart will help you diagnose engine problems in your
aircraft. (Views are Percentage views). Notice that there will be always
one CHT that is shown hotter than the others.
Display Symptom Probable Cause Recommended
Action
75° to 100°
EGT rise for
one cylinder
during flight
Spark plug not
firing due to fouling,
faulty plug, wire or
distributor.
Enrich mixture to
return EGT to
normal. Have plugs
checked.
EGT Increase
or decrease
after ignition
system
maintenance
Improper timing:
high EGT →
retarded ignition;
low EGT →
advanced ignition.
Check EGT for
each magneto to
determine any
uneven timing.
Loss of EGT
for one
cylinder.
Engine rough
Stuck valve. Other
cylinders are okay.
Have valve train
checked.
Loss of EGT
for one
cylinder; no
digital EGT
Failed probe
or
failed wire harness.
Swap probes to
determine if probe
or wire harness is
bad.
Decrease in
EGT for one
cylinder
Intake valve not
opening fully; faulty
valve lifter.
Have valve lifter or
rocker arm
checked.
Decrease in
EGT for one
cylinder at low
RPM
Low compression. Check
compression.

J.P. Instruments EDM-700 Specifications

General

Brand	J.P. Instruments
Model	EDM-700
Category	GPS
Language	English