IO-390-D Series Engine Maintenance Manual
12-30
© 2020 Avco Corporation. All Rights Reserved
Page 84
March 2020
IO-390-D Series Engine Maintenance Manual
Table 1 (Cont.)
Fault Isolation Guide
Problem
Cause
Corrective Action
Ref.
Engine will not start
or starts with
difficulty (Cont.)
Fault in the ignition
system
1.
Visually examine the harness for
physical damage.
2.
Examine leads using a high-tension
lead tester.
3.
Replace worn or damaged
components as necessary.
4.
Complete the following procedures:
•
Spark Plug Removal
•
Ignition Harness Inspection
•
Spark Plug Inspection
•
Spark Plug Cleaning
•
Spark Plug Gap Setting
•
Spark Plug Rotation
•
Spark Plug Installation
74-20
05-30
Damaged or worn
ignition lead
Ignition Harness Removal
Ignition Harness Inspection
Ignition Harness Installation
74-20
Incorrect EIS-to-engine
timing
Refer to the “EIS Troubleshooting
Guide” in this chapter.
Magneto incorrectly
timed to engine.
Complete the “Magneto-to-Engine
Timing Check.”
74-30
Magneto internal timing
not adjusted correctly or
"E" gap drifting because
of point or follower wear.
Replace magneto with a serviceable
unit as per the “Magneto Replacement
Procedure.”
74-30
Water in fuel system
Drain the fuel lines.
AMM
Rough Idle
Fault in the ignition
system
1.
Visually examine the harness for
physical damage.
2.
Examine leads using a high-tension
lead tester.
3.
Replace worn or damaged
components as necessary.
4.
Complete the following procedures:
•
Spark Plug Removal
•
Ignition Harness Inspection
•
Spark Plug Inspection
•
Spark Plug Cleaning
•
Spark Plug Gap Setting
•
Spark Plug Rotation
•
Spark Plug Installation
74-20
05-30