Thermo King MD-MT, Operator'S Manual

Page: 90 / 192

Engine Maintenance
90
Integral Fuel Solenoid
The fuel stop solenoid is located on the end of the
fuel injection pump.
Operation of the TK 3.74 engine is controlled by
the operation of the fuel solenoid and the throttle
(high speed) solenoid. 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”
position. When pushed out, this causes the
governor linkage to move the injection pump rack
to the “Fuel Off” position.
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 tension 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.
1. Throttle Lever (P/N 11-6129) 6. Eye Bolt (P/N 55-2762)
2. Fuel Stop Solenoid (P/N 41-1386) 7. Boot (P/N 91-3095)
3. Low Speed Adjustment Screw 8. Throttle Solenoid (P/N 44-9181)
4. Rod (P/N 11-7817) 9. Ball Joint (11-6820)
5. Clevis Pin (11-4266)
Figure 43: Integral Fuel Solenoid Components