Rough Engine Operation Or Loss Of Power; Carburetor Icing/Spark Plug Fouling; Magneto Malfunction; Engine-Driven Fuel Pump Failure - Cessna TR182 1979 Pilot Operating Handbook

SECTION 3
EMERGENCY PROCEDURES
CESSNA
MODEL TR182
ROUGH ENGINE OPERATION OR LOSS OF
POWER
CARBURETOR ICING
An unexplained drop in manifold pressure and eventual engine
roughness may result from the formation of carburetor ice. To clear the ice,
apply full throttle and pull the carburetor heat knob full out until the
engine runs smoothly; then remove carburetor heat and readjust the
throttle. If conditions require the continued use of carburetor heat in cruise
flight, use the minimum amount of heat necessary to prevent ice from
forming and lean the mixture for smoothest engine operation. At high
altitudes, manifold pressure drop with the application of carburetor heat
may be as much as 10 inches Hg. In this case, advance the throttle as
necessary to obtain the desired power or full throttle, whichever is less.
SPARK PLUG FOULING
A slight engine roughness in flight may be caused by one or more
spark plugs becoming fouled by carbon or lead deposits. This may be
verified by turning the ignition switch momentarily from BOTHto either L
or R position. An obvious power loss in single ignition operation is
evidence of spark plug or magneto trouble. Assuming that spark
plugs are
the more likely cause, lean the mixture to the recommended lean setting for
cruising flight. If the problem does not clear up in several minutes,
determine
if
a richer mixture setting will produce smoother operation. If
not, proceed to the nearest airport for repairs using the BOTH position of
the ignition switch unless extreme roughness dictates the use of a single
ignition position.
MAGNETO MALFUNCTION
A sudden engine roughness or misfiring is usually evidence of
magneto problems. Switching from BOTHto either L or R ignition switch
position will identify which magneto is malfunctioning. Select different
power settings and enrichen the mixture to determine if continued opera-
tion on BOTH magnetos is practicable. If not, switch to the good magneto
and proceed to the nearest airport for repairs.
ENGINE - DRIVEN FUEL PUMP FAILURE
In the event of an engine-driven fuel pump failure, gravity flow will
provide sufficient fuel flow for level or descending flight. However, in a
climbing attitude or anytime the fuel pressure drops to 0.5 PSI, the
auxiliary fuel pump should be turned on.
3-16 1 October 1978