Step 3. Engine Run-Up - Lycoming IO-390-D Series Installation And Operation Manual

IO-390-D Series Engine Installation and Operation Manual
15. Move the throttle slowly and smoothly to the IDLE rpm.
CAUTION
NOTICE: Unstable oil pressure or oil pressure less than 25 psi (172 kPa) could be an
indication of obstructed or interrupted oil flow or air in the oil lines. In this case,
stop, identify and correct the cause.
The engine is warm enough for take-off when the throttle can be opened without the
engine faltering.
Upon engine start, if smoke comes from a newly installed engine, after the first start,
there could have been some preservative oil in the cylinders, induction system,
and/or fuel nozzles/lines. If oil pressure is normal and the engine operates smoothly,
continue to operate the engine until the smoke clears. Otherwise, stop the engine,
identify and correct the cause.
16. Let the engine operate at 1000 rpm for approximately 3 minutes.
17. Look for any illuminated caution or warning lights in the cockpit.

Step 3. Engine Run-Up

WARNING
IF DURING ENGINE RUN-UP OR ENGINE IDLE, ANY OPERATIONAL
PROBLEMS OCCUR, DO NOT TAKE-OFF. IDENTIFY AND CORRECT
THE CAUSE OF THE PROBLEM AND COMPLETE THE OPERATIONAL
TEST IN THE "FIELD RUN-IN" CHAPTER AGAIN.
Complete the engine run-up as follows:
1. Make sure the oil pressure is within the specified limits (Appendix A).
2. Complete a magneto drop-off check as follows for all three cycles RIGHT/LEFT/BOTH.
A. Operate the engine at approximately 2100 to 2200 RPM.
NOTICE: To prevent spark plug fouling, do not operate on a single magneto for too long a
period. A few seconds is usually sufficient for the magneto drop-off check.
B. Switch from BOTH magnetos to left magneto and record the drop-off; return to BOTH
until the engine regains speed and switch to the right magneto and record the drop-off,
then return to BOTH. Drop-off must not exceed 175 rpm and must not exceed 50 rpm
between magnetos.
C. If the rpm drop exceeds 175 rpm, slowly lean the mixture until the rpm peaks. Then
retard the throttle to the specified rpm, for the magneto drop-off check and repeat the
check. If the drop-off does not exceed 175 rpm and the difference between the drop-off
values for both magnetos does not exceed 50 rpm, and the engine is running smoothly,
the ignition system is operating properly.
D. Smooth operation of the engine with a drop-off that exceeds the specification of 175 rpm
is usually an indication of a propeller load condition at a rich mixture.
WARNING
3. Make sure the oil pressure and oil temperatures are within the specified operating range in
Appendix A.
© 2020 Avco Corporation. All Rights Reserved
March 2020
DO NOT OPERATE THE ENGINE IF THE OIL PRESSURE IS LOW. IF
THE ENGINE IS OPERATED AT LOW OR NO OIL PRESSURE, THE
ENGINE CAN MALFUNCTION OR STOP.
IF THE ENGINE IS OPERATED AT LOW OIL PRESSURE OR LOW OIL
LEVEL, THE ENGINE CAN MALFUNCTION OR STOP.
Engine Operation
Page 37