b. As the flyweights swing out, the sliding gear is
its helical spline causes a slight change in the rotational
relationship in the injection pump to the engine, causing
forced toward the timing device hub.
injection to begin slightly earlier in the power stroke.
The longitudinal movement of the sliding gear on
Section VII. COLD WEATHER STARTING AIDS
the Instrument panel.
5-31. Purpose. Diesel engines are very difficult to
start In cold weather. This Is due mainly to the low
(3) The Intake manifold flame heater system has a
volatility of the fuel. The two most popular methods of
filter to remove Impurities from the fuel before it reaches
assisting a diesel engine in starting are:
a. Preheating the Induction air In the Intake
(4) Two fuel solenoid valves are used In the flame
manifold so that adequate vaporization will take place for
The valves are energized (open)
whenever the flame heater system is activated. The
valves ensure that fuel Is delivered only when the system
b. Injecting a fuel Into the engine that remains
Is operating. They stop fuel flow the Instant that the
volatile enough In cold weather to initiate combustion.
engine, or heater system, is shutdown.
Intake Manifold Flame Heater System (Fig.
Ether Injection System (Fig. 5-28).
a. General. The ether Injection system assists In
a. General. Engines are equipped with a flame-
the cold weather starting of a diesel engine by Injecting
ether Into the Intake manifold.
Ether, which is very
cold weather starting and warm-up operations.
volatile, will vaporize readily In cold weather, Initiating
The flame heater assembly is
composed of a housing, spark plug, flow control nozzle,
A pressurized canister containing
and two solenoid control valves.
The spark plug Is
ether Is fitted to the engine. The flow of ether from the
energized by the flame heater Ignition unit. The nozzle
canister to the spray nozzle Is controlled by a solenoid
sprays fuel under pressure Into the Intake manifold
valve that closes when it is de-energlzed. This solenoid
elbow assembly. The fuel vapor is Ignited by the spark
Is controlled by a push-button switch on the Instrument
plug and burns In the Intake manifold, heating the air
before it enters the combustion chambers.
(1) When the switch Is pushed, the solenoid is
(1) Because this system uses fuel from the fuel
energized. This opens the ether canister. Pressure
tank of the vehicle, its components must be compatible
from the canister pushes ether through a connecting
with all approved fuels when the system Is used with a
tube to the nozzle, where it discharges Into the Intake.
(2) The system contains a coolant temperature
(2) The flame fuel pump assembly Is a rotary
sensor that will keep the system from functioning when
type, driven by an enclosed electric motor. The fuel
coolant temperature is above 50F(100C).
pump receives fuel from the vehicle fuel tank through the
vehicle's supply pump and delivers It to the spray nozzle.
The pump Is energized by an ON-OFF switch located on