J.P. Instruments EDM-960

For Your Safe Flight Page | 11
Display
Symptom
Probable
Cause
Recommended
Action
Rapid rise in
CHT of one
cylinder
Detonation.
Reduce power.
Sudden off
scale rise for
any or all
cylinders
Pre-ignition - >
Normalize view - >
or failed probes - >
Full rich & reduce
power.
Change to
Standard view
Check probes
(no picture)
Loss of peak
EGT
Poor ignition or
vapor in fuel
injection system.
Have magneto
tested.
(no picture)
Decrease in
peak or flat
EGT response
to leaning
process
Detonation. Usually
the result of 80
Octane fuel in 100
Octane engine.
Enrich mixture,
reduce power and
re-lean mixture.
Repeat to find
power setting
where normal peak
is obtained or run
rich.
Below 10,000
ft. full throttle
causes EGTs
to rise
Weak or defective
mechanical fuel
pump.
Apply booster
pump. If EGTs
drop, replace fuel
pump.