Piper Navajo PA-31 Service Manual page 971

PIPER NAVAJO SERVICE MANUAL
TABLE XIII-I. TROUBLESHOOTING CHART (HEATING SYSTEM) (cont.)
Trouble
Cause
Remedy
Heater fires but burns
unsteadily. (cont.)
Spark plug partially
fouled.
Replace spark plug. (Re-
fer to Paragraph 13-27.)
(See Caution.)
CAUTION
Do not create a spark gap by holding the lead to the heater jacket.
This can result in damage to the lead and ignition unit and the
operator may receive an electrical shock.
Loose primary connec
at ignition assembly.
Faulty vibrator.
Combustion air biowe
speed fluctuates. (Can
be caused by low volt-
age, loose blower
wheel, worn brushes o
motor.
High voltage leak in
lead between ignition
assembly and spark
plug.
Inoperative ignition
assembly.
Restriction in fuel
nozzle orifice.
Nozzle loose in retain-
er or improper spray
angle.
:tion
r
r
Tighten the connection.
Replace the vibrator. (Re-
fer to Paragraph 13-33.)
Remove and overhaul the
combustion air blower
assembly as required or
correct low voltage con-
dition. (Refer to Para-
graphs 13-27, 13-41,
13-45 and 13-48.)
Replace ignition assembly.
(Refer to Paragraph 13-29.)
If vibrator is in good
condition, replace ig-
nition assembly only.
(Refer to Paragraph 13-29.)
Remove nozzle for clean-
ing or replacement. (Re-
fer to Paragraphs 1340,
13-44 and 13-47.)
Tighten or replace the
nozzle as required. (Re-
fer to Paragraphs 1345
and 1347.)
HEATING AND VENTILATING SYSTEM
Reissued: 10/12/79
5D17