Thermo King KD-II SR, Manual

Page: 103 / 182

Engine Maintenance (Rev. 04/03)
89
TK 3.74 ENGINE
Operation of the TK 3.74 engine is controlled by the opera-
tion of the fuel solenoid and the throttle (high speed) sole-
noid. The fuel solenoid consists of a spring loaded plunger
and electro-magnetic coil. When the engine is OFF, spring
tension on the plunger maintains the plunger’s “out” posi-
tion. When pushed out, this causes the governor linkage to
move the injection pump rack to the “Fuel Off” position.
1. Fuel Stop Solenoid
2. Fuel Injection Pump Groove
3. O-Ring
Fuel Solenoid Components
When the fuel solenoid is energized, current is applied to
the coil creating an electro-magnetic field, which pulls the
When in the “pulled-in” position, the plunger releases ten-
sion on the governor linkage. The governor linkage then
moves the fuel injector rack, thus controlling the fuel flow
and placing it in the “Fuel On” position.
Adjustments made to the throttle (high) speed solenoid
change governor spring tension which in turn adjust speed
settings.