Low Power And Uneven Running - Piper PA-44-180 SEMINOLE Maintenance Manual

CHART 7101. TROUBLESHOOTING (ENGINE) (cont)
TROUBLE
Failure of engine to idle
properly. (cont)
Low power and uneven
running.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
CAUSE
Sniffle valve stuck open, 180T
only.
Fouled spark plugs.
Incorrect idle adjustment.
Uneven cylinder compression.
Faulty ignition system.
Insufficient fuel pressure.
Mixture too rich; indicated by
sluggish engine operation, red
exhaust flame at night.
Extreme cases indicated by
black smoke from exhaust.
Mixture too lean; indicated
by overheating and backfiring.
Leaks in induction system.
Defective spark plugs.
Improper fuel.
Magneto breaker points not
working properly.
Defective ignition wire.
Defective spark plug terminal
connectors.
Sniffle valve stuck open, 180T
only.
3E1
REMEDY
Clean or replace valve.
Clean or replace plugs.
Adjust throttle stop to obtain
correct idle.
Check condition of piston rings
and valve seats.
Check entire ignition system.
Adjust fuel pressure.
Readjustment of carburetor
by authorized personnel is
indicated.
Check fuel lines for dirt or
other restrictions.
Tighten all connections.
Clean and gap or replace
spark plugs as necessary.
Drain fuel tank and refill with
recommended grade fuel.
Clean points. Check internal
timing of magnetos.
Check wire with electric tester.
Replace defective wire.
Replace connections on spark
plug wire.
Clean and/or replace valve.
Refer to sniffle valve this chapter.
Page 71-03
Revised: May 15, 1989
7 1 - 0 2 - 0 0