THEORY OF OPERATION
ENGINE COMPONENTS (Continued)
Smoke Generating System:
The smoke generating system uses the engine fuel pump to supply diesel fuel, from the vehicle
fuel tanks, to two solenoid valves mounted at the rear of the engine. When the solenoid valves
are energized (opened) they allow diesel fuel to be sprayed into the engine exhaust system.
The fuel vaporizes and exits together with the engine exhaust gases. The fuel vapor cools on
contact with the ambient air and condenses to form a dense homogeneous smoke screen. The
electrical power to energize the solenoid valves is supplied by the vehicle air cleaner blower
motor circuit on Model AVDS-1790-2CA, -2DA engines, and the warning indicator and
warning horn circuit on the Model AVDS-1790-2DR engine. This prevents accidental
activation of the smoke generating system when the engine is not running.
When the engine is running on JP8 fuel, the fuel cutoff valve for the
smoke generator system must be safety-wired in the OFF position.
WP 0004 00-26