FUEL SYSTEM - TM-9-2815-204-350022

f. Fuel Hoses and Tubes. The fuel supply

d. Thermostat. Cent rol of coolant flow from

theheated engine to the radiator is maintained

pump-to-fuel filter inlet hose. fuel iniection

by a thermostat installed in a housing at the

pump inlet hose, and fuel injection pump fuel

front of the intake manifold. The thermostat is

return hose are made of a flexible rubber com-

The six fuel injection tubes are

set to open at 180 F.

position.

soft annealed steel tubing, subjected to high

31. FUEL SYSTEM (Fig. 21)

fuel pressure during operation. The tubes are

the same length and convey fuel from the fuel

a. General. The fuel system used on the

injection pump head to each individual fuel in-

engine makes it possible for the engine to op-

jector nozzle and holder assembly. The fuel

erate on various types and grades of fuel

injector nozzle holder fuel return and fuel ex-

without adjusting the fuel injection pump.

cess tubes are made of nylon composition.

b. Fuel Supply Pump. The fuel supply pump

32. INTAKE MANIFOLD FLAME HEATER AND

is part of the fuel injection pump assembly. The

FUEL SYSTEM

pump takes fuel from the vehicle fuel tank and

delivers it under pressure through the primary

a. General. The engine is equipped with a

and final fuel filters to the fuel injection pump.

flame type manifold heater (fig. 22) for heating

The injection pump then meters the fuel to the

the induction air during cold weather starting

fuel injector nozzle and holder assemblies in

and warmup operation.

firing order sequence. Refer to TM 9-2910-

223-35 for a complete detailed description of

b. Flame Heater Assembly. The flame heater

fuel supply pump.

assembly is composed of a housing, spark plug,

Primary and Final Fuel Filters. The pri-

and spray nozzle and holder assembly. The

mary and final fuel filters are identical and

nozzle sprays fuel under pressure into the in-

have interchangeable and replaceable elements.

take manifold elbow assembly. The fuel vapor

The primary fuel filter removes most foreign

is ignited by the spark plug and burns in the

material from the fuel. The final fuel filter

manifold, heating the air before it enters the

removes any remaining foreign material which

engine combustion chambers. The spark plug is

has escaped the filtration of the primary fuel

energized by the flame heater ignition unit

filter.

which is mounted on the `intake manifold elbow

studs .

d. Fuel Injection Pump Assembly. The fuel

injection pump assembly is driven by the fuel

c. Flame Heater Fuel Pump Assembly. The

injection pump driven gear which in turn is

flame heater fuel pump assembly is mounted on

driven by the camshaft gear (fig. 17). The pump

a bracket near the lower right front of the en-

is used to supply pressurized fuel to each in-

gine. The fuel pump is a rotary type driven by

dividual fuel injection nozzle and holder assem-

an enclosed electric motor. The pump is capable

bly in the firing order sequence. The fuel in-

of pumping 2.0 gallons of fuel per hour at a

jection pump advance unit automatically pro-

pressure of 90 psi. The pump draws fuel from

vides a gradual 8 degrees advance of fuel

the vehicle fuel tank and supplies it to the flame

injection timing over the engine speed range.

heater spray nozzle and holder assembly. The

For complete description, data, and maintenance

fuel pump is energized by an on-off switch on

of this pump, refer to TM 9-2910-223-35.

the vehicle instrument panel.

d. Flame Heater Fuel Filter Assembly. The

e. Fuel Injector Nozzle and Holder Assem-

flame heater fuel filter assemblv is mounted

blies. The six fuel injector nozzle and holder

on the same bracket that mounts the flame

assemblies are used to inject fuel into the com-

heater fuel pump. The filter element is re-

bustion chambers (fig. 14}. The injector nozzle

placeable.

and holder assemblies are sealed against leak-

age by copper gaskets. The fuel injector nozzle

and holder assemblies are interconnected by

e. Flame Heater Solenoid Valves. Two flame

fuel return tubes to return excess fuel to the

heater fuel solenoid valves (fig. 22) are used.

fuel tank. The nozzle and holders are adjust-

The valves, identical and interchangeable, are

able to provide a proper opening pressure and

energized (opened) whenever the flame heater

spray pattern for economical engine operation

assembly and flame heater fuel pump are actu-

and proper performance.

ated. These valves insure that fuel is delivered