J.P. Instruments EDM-900 Manual

For Your Safe Flight Page 1
Pilot’s Guide
Engine Data Management
EDM-900
Primary
TSO/STC
Copyright 2011 J.P. Instruments, Inc.
All Rights Reserved
J.P. INSTRUMENTS INC.
Information: P. O. Box 7033
Huntington Beach, CA 92646
Factory: 3185-B Airway Ave.
Costa Mesa, CA 92626
[phone] Fax [phone]
www.jpinstruments.com
Printed in the United States of America Rev B

Page 2 Engine Data Management
Table of Contents
Section 1 - Section-1 Getting Started 5
View Angle 5
Rotation 7
Fuel Flow Computer Basics (independent of fuel quantity) 7
Display Screen Basics 8
Horizontal Display Mode 8
Vertical Display Mode 9
Remote Annunciate Light Basics 9
RPM and MAP Display Basics 10
Linear Bar Graph Display Basics 10
LeanFind Basics 12
Section 2 - Interpreting Data 13
Operation for each Phase of Flight 13
Typical Normal Measurements 15
Section 3 - Displays and Controls 18
Control Buttons 18
Scanner Displays 20
Additional Displays Hobbs, Revisions, and Alarm Limits 22
Dimming the Display 23
Section 4 - Operating Modes 23
Automatic Mode 23
Manual Mode 24
Section 5 - Lean Find 26
Lean Find Procedure—General Explanation 31
Expanded Leaning Procedures 34
Common Misapplications 35
Section 6 - Fuel Flow Operation 36
Fuel Management 36
Start Up Fuel 37
Resetting ‘USD’ 38
Trip Mode (Accumulate Trip Totalizer) 38
Scanner Fuel Flow Display Select 38
Section 7 - Alarms 39
Section 8 - Memory and Data Download 40
Downloading Data from the EDM 40
Transferring data from the USB Flash Drive to a PC 41
Section 9 - First Time Setup and Customization 41
Section 10 - Adjusting Manifold Pressure & %HP 46
Adjusting the HP Constant for Rich of Peak Operation 46
Adjusting the MAP 46
Adjusting the HP Value 47
Section 11 - Programming the Fuel Flow 48
Fuel Flow K factor 48
Programming Trip Mode 51
Setting the GPS Com Format 51

For Your Safe Flight............................................... Page 3
Troubleshooting the EDM 53
Diagnostic Testing on Startup and During Flight 53
Diagnostic Messages 53
Section 12 - Appendices 55
Shock Cooling (CLD) 55
Navigation Data Formats 57
Navigation Data Ports for GPS Comm 57
Interface connections to selected GPS models 57
Section 13 - Technical Support 58

Page 4 Engine Data Management
Product Features
Hands-free, automatic scanning
Lean Findfinds the first and last cylinder to peak with
true peak detect—eliminates false peaks
Displays both leaned temperature below peak and peak
Battery voltage with alarm
Amperes (load or charge/discharge meter)
Programmable alarm limits
Exhaust Gas Temperatures (EGTs) to stable 1°F
resolution
DIF low to high EGT with alarm
Shock cooling monitored on every cylinder
Fast response probes
Non-volatile long term memory
Records and stores data up to 30 hours
Post-flight data retrieval
Data retrieval software
Oil pressure
Oil temperature
Turbine inlet temperature, if applicable (optional)
Outside air temperature
Compressor discharge temperature (optional)
Carburetor temperature or induction temperature
(optional)
Fuel pressure, if applicable
Fuel level Voltage, Resistive or Capacitive (frequency)
Fuel Flow
Solid-state rotor fuel flow transducer
Fuel quantity in gallons, kilograms, liters, or
pounds
Low fuel quantity alarm
Low fuel time alarm
GPS interface
Instantaneous fuel flow rate
Total amount of fuel consumed
Total fuel remaining
Time to empty at the current fuel flow rate
RPM and manifold pressure
Automatically calculates percent horsepower
Hobbs® timer
Remote Auxiliary Display (RAD)

For Your Safe Flight............................................... Page 5
Section 1 - Section-1 Getting Started
This is a summary of basic operation. Detailed descriptions of all
operations appear later in this Pilot’s Guide.
EDM-900 primary instrument has preset alarm limits and
cautionary ranges per the POH (user cannot change them)
typically for the following measurements of: oil temperature, oil
pressure, fuel pressure, fuel quantity, cylinder head temperature,
turbine inlet temperature, manifold pressure, and RPM.
Note: Fuel quantity gauges must be calibrated to the aircraft and
will not be functional until the fuel calibration process has been
performed.
View Angle
The best view angle for the pilot is in the horizontal mode with the
buttons on the bottom. The best Portrait mode is with the buttons
on the right.
View angles are per the table below:
Horizontal
Left
65 Degrees
Viewing
Right
65 Degrees
angle
Vertical
Up
60 Degrees
Down
50 Degrees

Page 6 Engine Data Management
List of abbreviations and acronyms
Gauge Function
Message Area
Alarm Abbreviation
Primary
Primary
Engine rotational speed
RPM xxxx
Engine Manifold Pressure
MAP xx.x in hg
Engine Cylinder Head Temp
CHT2 xxx oF
Engine Oil Temperature
O-T xxx oF
Engine Oil Pressure
O-P xxx oF
Fuel Pressure
F-P xx PSI
Fuel Flow to engine
F-F xx.x GPH
Comp. Discharge Temp.
CDT xxx oF
Turbine inlet Temp. Left side
TIT-L xxxx oF
Turbine Inlet Temp. Right side
TIT-R xxxx oF
Single Turbine Inlet Temp.
TIT xxxx oF
Non-Primary
Non-Primary
Exhaust Gas Temp.
EGT2 xxxx oF
Shock Cooling of CHT
CLD xx o/MIN
Differential Temp. of EGT
DIF xx oF
Bus Voltage
Volts xx.x
Amperage Load
AMPS xx
Outside Air Temp.
OAT xx oF
Estimated Time to Empty
Est. T to E xx:xx H:M
Fuel used to date
USED xx.x GAL
Estimated Remaining fuel
Est. REM xx GAL
Estimated Fuel required to Waypoint
Est. WP REQ xx GAL
Estimated Fuel Remaining at
Waypoint
Est. WP RES xx GAL
Nautical Miles per Gallon
ECON xx.x MPG
Brightness, Dim control
DIM/BRT

For Your Safe Flight............................................... Page 7
Rotation
Holding the step button in for 5 seconds, with the engine OFF, will
produce the gray arrow. This arrow can be rotated to a new up position
by tapping the LF button to rotate and then the STEP button for save. If
you chose the one bad angle (Landscape mode with the buttons on top
and the JPI logo upside down), return the instrument to JPI and JPI will
rotate the screen with the buttons on the bottom.
Fuel Flow Computer Basics (independent of fuel quantity)
The fuel flow computer tracks the fuel flowing to the engine and
computes various values based on this. At installation, then each time
you refuel the aircraft, you must inform the EDM about how much
useable fuel is onboard. This is done via the REFUEL function.
See page 36 for detailed information
Control Button Basics
Four operating buttons control all functions of the EDM. These buttons
change labels depending on the current state of the EDM.
STEP LF DIM
(3rd)ALL /TEMP/FUEL (1st) (2nd) (4th)

Page 8 Engine Data Management
Display Screen Basics
The display screen is arranged into three sections. The top left is the
MAP and RPM section. The bottom left is the Scanner® section or
message area. On the right side are the horizontal primary strip gauges.
Non-Primary gauges have a digital read out only. The instrument ranges
and alarm limits are configured to match those of your aircraft POH when
the EDM is set up as a Primary instrument. TIT column is to the right of
the last EGT/CHT when applicable.
Horizontal Display Mode

For Your Safe Flight............................................... Page 9
Vertical Display Mode
Remote Annunciate Light Basics
The Remote Annunciator Light ‘RAL’
provides notification that an alarm is present
in the display, for all Primary gauges. Upon
power up, the RAL shows Red and yellow
indicating it is functional. Before each flight,
confirm that it is functional. Non-functioning
RAL must be repaired before flight.
Remote
Annunciator Light
(RAL)

Page 10 Engine Data Management
Horizontal mode Vertical mode
RPM and MAP Display Basics
In the vertical mode to the right and the
Horizontal mode above MAP (Manifold Pressure)
and RPM (Revolutions per Minute) are shown.
Operations exceeding red line cause the digital
value to turn red or yellow with the RAL coming
on and a digital value in the Scanner message
area.
Linear Bar Graph Display Basics
The Bar Graphs section contains dedicated bar graphs with digital
display. An example is shown here. Pointers move horizontally left to right
showing value changes and digital readouts turn red
when primary
exceedances
occur. Non
primary
functions flash
white.
Horizontal/Landscape mode Vertical/Portrait mode

For Your Safe Flight............................................. Page 11
Scanner® Information Area
The Scanner® Information Area provides expanded information in the form of
alpha-numeric messages, parameters and calculations. In Auto-Scan,
parameters will ‘scan by’ once every 4 seconds (default). This rate can be
changed in Pilot Programming Mode. Tap the STEP button for ‘Manual’ selection
of any parameter. Parameters for the installed options will be displayed. To start
the automatic scan tap LF and then STEP.
DISPLAY
PARAMETER
DESCRIPTION
EGT 1436 CHT 382
EGT/CHT
Shows successive pairs of EGT &
CHT per STEP tap.
TIT 1580 oF
TIT
Single Turbine Inlet Temp.
TIT-L and -R 1490
oF
TIT-L, TIT -R
Two Turbine Inlet Temp. Left and
Right engine side
Oil-T 204 oF
OIL TEMP
Oil temperature in degrees F
Oil-P 64 PSI
OIL PRES
Oil pressure in psi
F-P16 PSI
FUEL PRES.
Fuel pressure in psi
F-F 2.7GPH
FUEL FLOW
Fuel flow in GPH
CLD 75 oF
SHOCK COOL
CHT cooling rate (deg/min)
VOLTS 13.9
BATTERY
Battery/Bus voltage
AMPS -6
Amperage
Set up per the specific aircraft
OAT 23 oF
OAT
Outside air temperature F or C
DIF 40 oF
DIF
Hottest minus coldest EGT
CRB 56 oF
CRB
Carburetor Air Temp (only allowed if
IAT not present)
CDT 145 oF
CDT
Compressor Discharge Temp (only
allowed if CRB not present)
IAT 105 oF
IAT
Induction Air Temp
Est. REM 68.0 GAL
FUEL
REMAINING
Calculated fuel remaining on board
based on what the pilot put in as
maximum.
WP REQ 12.7 GAL
FUEL
REQUIRED
Calculated fuel required to reach
waypoint or destination (GPS
interface must be corrected)
Est. WP REM 63 GAL
FUEL
RESERVE
Calculated fuel reserve at waypoint
(GPS interface must be correct)
ECON 9.8 MPG
Nautical MILES
PER GALLON
Calculated fuel miles per units
(GPS interface required)
EST. T to E 04:32
H:M
Estimated Time
to Empty
Calculated time remaining to fuel
exhaustion in Hours and Minutes at
present power.
GPH 15.0 GPH
FUEL FLOW
RATE
Actual fuel flow rate in Gallons per
hour
USD 7.2 GAL
FUEL USED
Actual fuel used by the engine
FUEL-P 64 PSI
FUEL PRES
Fuel pressure in PSI

Page 12 Engine Data Management
LeanFind Basics
Simply pre-lean, tap the LF button
(Lean Find) and begin leaning. The
EDM will assist you in finding the first
cylinder to peak. This example is for
Rich of Peak, ROP. See page 26 for
a more detailed description of
leaning. Press LOP to exit the ROP
mode and enter the LOP mode.
1. Establish cruise at approximately 65 to 75% power and pre-lean the
mixture to 50°F estimated rich of peak EGT on any cylinder.
2. Wait about 30 seconds, then tap the LF button.
3. Begin leaning the mixture smoothly without stopping. Turn a Vernier
about ¼ turn per second; retract a non-Vernier or quadrant lever so
that EGT rises about 10°F per second.
4. Stop leaning when you see LEANEST for two seconds, followed by—
for example—EGT1449 FF14.7 The left number is the current
temperature of the first EGT to peak and the right number is the
current fuel flow.
5. Now tap the PEAK button to display the EGT difference from peak
which is very useful for setting desired degrees below peak.
6. Slowly enrich the mixture noting that the EGT difference diminishes
as EGT climbs back to peak, followed by it going minus again. Stop
enriching at the desired EGT difference (such as ‘EGT -75’).
7. You can also see what the peak EGT was by holding the PEAK
button.
8. Tap STEP to
exit the Lean
Find Mode.

For Your Safe Flight............................................. Page 13
Section 2 - Interpreting Data
Operation for each Phase of Flight
(Worth adding to your run-up checklist)
Engine
Run-Up
Suggested setup:
Set engine to run-up RPM
Normalize view:
Manual mode
Verify:
Uniform rise of about 50°F in all EGTs in single
magneto operation.
Uniform rise of EGTs with application of the mixture
control.
Be alert for:
unusually low voltage (less than nominal battery
voltage)
cold OIL and normal oil pressure
abnormally high CHT
Large drop in EGT on one cylinder in single magneto
operation—may be fouled spark plug.
Take-Off,
Climb, and
Full
Throttle
Operations
Suggested setup:
Standard view
Automatic mode
Verify:
EGTs and CHTs consistent with past climbs. EGTs
should be in the 1100 to 1300°F range (100° to 300°F
cooler than cruise) due to fuel cooling.
Be alert for:
High EGT in one cylinder, 300°F above the others may
indicate plugged injector or leaking manifold gasket on
a carbureted engine. At high density altitude an overly
rich mixture can significantly reduce engine power.
If all EGT columns go off scale to the top of the
column, be sure you are not in Normalize view, as
indicated by the symbol NRM above the Scanner®
section.

Page 14 Engine Data Management
Cruise
After the engine is warmed up, use Lean Find to lean the
mixture.
Suggested setup:
Normalize view
Automatic mode
Be alert for:
Uneven EGTs (injected engines). Make fine
adjustments to throttle, then RPM, then mixture to
level the display columns.
Abnormal patterns of EGTs and CHT. (see Engine
Diagnosis Chart on page 16).
Descent
Suggested setup:
Standard view
Manual mode
Be alert for:
CLD: shock cooling alarm is set to -60°F. Average
cool rates of -40°F/minute to -50°F/minute are normal,
depending on the engine size.

For Your Safe Flight............................................. Page 15
Typical Normal Measurements
The following chart lists typical normal measurement values that you will
observe for most general aircraft engines. Your particular engine’s
ranges may not fall within these values.
Measurement
Normal range
Comments
EGTs in Cruise
1350°F
1550°F
under 200 HP engines
high performance engines
(EGT should drop 200°F when
full throttle is applied)
EGT span (DIF)
70 to 90°F
120 to 150°F
fuel injected engines
carbureted engines
TIT
1600°F average
100° higher than EGT
CHTs
350°F (OAT 60°F)
410°F
normally aspirated engines
Turbocharged engines
CHT span
50 to 70°F
100° with gasket probes
OIL T
200°F
oil cooler thermostat typically
opens at 180°F
OIL P
30 to 60 psi
varies with aircraft type
FUEL P (injected)
14 to 18 psi
varies with aircraft type
FUEL P (carbureted)
0.5 to 8 psi
Shock cooling*
-40°/minute
-55°/minute
-200°/minute
tightly cowled engines
Bonanza
helicopter
* Maintain a cooling rate magnitude of less than -50°/minute. You will find
that the cylinder with the greatest shock cooling may shift from front
cylinders (during climb out) to the rear cylinders (during descent ).

Page 16 Engine Data Management
Engine Diagnosis Chart
The following chart will help you diagnose engine problems in your
aircraft.
Display
Symptom
Probable
Cause
Recommended
Action
TIT ~100°
higher than
EGTs
This is normal
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
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.
Increase in DIF
at low RPM
Low compression
(blow by) in cylinder
Check
compression.
EGT and CHT
not uniform
Normal for
carbureted engines.
Dirty fuel injectors or
fouled plugs.
Check injectors
and plugs.
Decrease in
EGT for all
cylinders
Decrease in airflow
into the induction
system. Carb or
induction ice.
Check for
change in
manifold
pressure.

For Your Safe Flight............................................. Page 17
Display
Symptom
Probable
Cause
Recommended
Action
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
CHT of one
cylinder
Detonation.
Reduce power.
Sudden off
scale rise for
any or all
cylinders
Pre-ignition
Normalize view
or failed probe
Full rich and reduce
power.
Change to Standard
view
Check probe.
(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 boost pump. If
EGTs drop, replace
fuel pump.
CHT more
than 500°,
EGT normal.
Adjacent EGT
may be low
Leaking exhaust
gasket blowing on
CHT probe.
Look for white
powder around
cylinder to determine
leak area.

Page 18 Engine Data Management
Section 3 - Displays and Controls
The EDM monitors engine temperatures, pressures and voltages, assists
in adjusting the fuel/air mixture, and helps diagnose engine malfunctions.
There are multiple components of the user interface:
Four front panel operating buttons below the bottom of the display.
RPM and MAP display in the upper left corner of the display
Scanner analog display including cylinder number and index square
in the lower left corner of the display
Scanner digital display for numeric readouts and messages at the
bottom left
Bar graph displays on the right half of the display
Control Buttons
Four operating buttons control all functions of the EDM. These buttons
may change labels depending on the current operating mode of the EDM.
The term tap is used to denote pressing a button momentarily. The term
hold is used to denote pressing and holding a button for five seconds or
longer. Button layout is shown below:
1st Button
In the Automatic mode, tapping the STEP button stops Scanner auto-
sequencing and changes to Manual mode. Each tap of the STEP
button then displays the next measurement in the sequence. Holding
the STEP button sequences in reverse order.
In the Lean Find mode tapping the EXIT button will terminate the
Lean Find mode and change to the Automatic mode.
In the Program mode tapping the NEXT button will advance to the
next item.
STEP LF DIM
(3rd)ALL /TEMP/FUEL (1st) (2nd) (4th)

For Your Safe Flight............................................. Page 19
2nd Button
In Automatic or Manual modes, tapping the LF button will activate the Lean
Find mode.
In the LF mode holding the LF button after peak EGT is found will display
the peak EGT.
In Automatic or Manual modes holding the LF button for three seconds will
toggle between Standard and Normalize (NRM) views.
In the programming mode, tapping the PLUS or MINUS button will allow you
to edit a parameter value.
Holding LF during power up will display the primary alarm limits after the
self-test is complete.
1st and 2nd Buttons
Holding both the STEP and LF buttons simultaneously for five seconds will
enter the pilot programming mode.
Just after entering Lean Find Mode (but before any EGT has risen), holding
both First and Second buttons for five seconds will toggle between LOP or
ROP leaning modes.
Tapping both the STEP and LF buttons simultaneously in Manual mode
toggles to ‘include’or ‘exclude’the displayed non-primary measurement
from the Automatic mode only.The excluded measurement will show up in
the manual mode.
3rd Button
Tapping DIM (brightness decreases) or holding DIM (brightness increases)
allows decrease or increase brightness respectively.
2nd and 3rd Buttons
Holding both the LF and DIM buttons simultaneously will display the Hobbs
readings. Tap button labeled NEXT to see additional information screens.
4th Button ( ALL/TEMP/FUEL )
Select what is shown during Scanner auto-sequence. Choices are ALL,
TEMP or FUEL. Highlighted one is what is active.

Page 20 Engine Data Management
Scanner Displays
Scanner EGT and CHT Analog Bar Graph
The height of each column represents a EGT or CHT or TIT (if installed)
temperature. Note: when in certain modes, such as leaning or normalize,
the EGT resolution will temporarily be finer.
Cylinder Numbers and Index
Just below the bar graph columns are numbers identifying the respective
cylinder. If TIT is installed, it is labeled by the letter Tunderneath. A
square ‘Cylinder I.D. Index’ surrounding a number indicates what cylinder
is currently selected and relates to the digital display.
Scanner Digital Display
Located under the Scanner bar graph area is the alphanumeric display. It
displays alphanumeric values for different parameters as well as status
and alarm messages.
Normalize / Standard View
To toggle between Standard and the Normalize views, hold the LF button
for three seconds until the NRM icon toggles on or off. Note: Normalize
cannot be activated while in Lean Find mode.
Standard view (when the NRM icon is not lit): the EGT top of the
columns represent absolute temperature.
Normalize view (when the NRM icon is lighted): When you change
to the Normalize view, all EGT columns are initially normalized to the
mid-point for deviation trend analysis. Any changes are shown as an
increase or decrease relative to the mid-point, thus giving an
instantaneous indication that an EGT has deviated. You normally use
normalize in level cruise, but it is also useful during steady state run-
ups. Note: A common misapplication is to be in the Normalize view
and then change power setting. This causes all columns to go off
scale, high or low. Select Standard view before changing power or
altitude.
Temperature Units (°F or °C)
The EDM can display engine temps in either °F or °C (Fahrenheit or
Celsius). In Primary configurations, this is set to the same units as the
configuration the aircraft was originally certified to.