TM 9-2320-289-10.pdf

1-10. ENGINE
Section III. TECHNICAL PRINCIPLES OF OPERATION
TM 9-2320-289-10
a. The CUCV Series of trucks are powered by a V-8 diesel engine which has a displacement
of 6.2 liters. This engine is similar to a V-8 gasoline engine in many ways, but major differences occur
in cylinder heads, combustion chambers, fuel distribution system, air intake manifold, and method
of ignition.
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Fuel Distribution: There is no carburetor on a diesel engine. Instead, fuel is injected
under high pressure through nozzles into the combustion chamber at correct timing
intervals.
Ignition. Ignition of fuel occurs because of heat developed in combustion chamber.
As a result, no spark plugs or high voltage ignition system is required. For cold starts,
glow plugs heat up combustion chamber.
Air Intake Manifold. Air intake manifold is always open to atmospheric pressure. As
a result, the engine does not develop a vacuum supply. Therefore, the engine drives
a vacuum pump which supplies shift signals to the automatic transmission.
b. The lower engine (case, crankshaft, camshaft, bearings, rods, pistons, and wrist pins) is
similar to a gasoline engine, but is of a heavy-duty design because of greater stresses developed
in a diesel engine.
c. Here are some driving tips that will help you maintain good engine performance:
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1-11. FUEL SYSTEM
DO NOT make full-throttle starts and hard stops.
Take it easy when engine is cold. Maximum performance is reached at normal
operating temperatures.
DO NOT hold truck on an uphill grade with accelerator pedal. Use the regular brakes
to hold truck.
DO NOT use starter aids such as ether or gasoline in air intake system. Such aids can
cause immediate engine damage.
Pumping accelerator pedal before or during cranking will not help start engine.
When engine is cold, let it Idle for a few seconds before driving; this will allow proper
oil pressure to build up. (Increased operating noise and light exhaust smoke are normal
when engine is cold.)
If oil pressure light comes on while operating truck, IMMEDIATELY SHUT DOWN
ENGINE. Continued operation of engine while it is not being properly lubricated will
cause serious damage.
DO NOT use diesel fuel which has been contaminated with engine oils.
Maintain a minimum of 1/4 tank of fuel when temperatures are below 20 0
F.
DO NOT run engine at idle for extended periods of time; damage can occur to engine.
a. A combination of low pressure and high pressure pumping systems moves fuel from the
fuel tank to the engine.
b. Fuel is pumped from the fuel tank by a low pressure pump which moves fuel toward the
fuel filter that separates water and contaminants from the fuel. From the fuel filter, fuel is drawn
into the high pressure injection pump which meters and pressurizes fuel and sends it through high
pressure fuel lines into the injection nozzle located in the engine’s precombustion chamber.
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