MANIFOLD FLAME HEATER

The manifold flame heater (fig. 5-44) is another type of cold starting system found on diesel engines. This system is composed of a housing, spark plug, flow control nozzle, and two solenoid control valves. This system operates as follows:

• The flame heater ignition unit energizes the spark plug.
• The nozzle sprays fuel under pressure into the intake manifold assembly.
• The fuel vapor is ignited by the spark plug and burns in the intake manifold. The heat from this fire warms the air before it enters the combustion chamber.

The flame fuel pump assembly is a rotary type, driven by an enclosed electric motor. The fuel pump receives fuel from the vehicle fuel tank through the supply pump of the vehicle and delivers it to the spray nozzle. The on/off switch, located on the instrument panel, energizes the pump.

The intake manifold flame heater system has a filter to remove impurities from the fuel before it reaches the nozzle.

The two fuel solenoid valves are energized (open) whenever the flame heater system is activated. The valves ensure that fuel is delivered only when the system is operating. These valves stop the flow of fuel the instant that the engine or heater is shut down.

NOTE

When troubleshooting or repairing these units, you should consult the manufacturer's service manual.