Jeep UNIVERSAL CJ-2A - Page 23

c
TUNE-UP
FIG. 26-T!MING MARKS (Early Engines)
spark plug and turn the engine over until No. 1
piston is on compression stroke as indicated by
air being forced from No. 1 spark plug opening.
Turn the engine slowly until the 5o BTC mark on
the timing gear cover is in alignment with the
notch on the crankshaft pulley. Fig. 26 shows the
timing pointer arrangement used on early engines;
Fig. 2 7 shows the timing pointer arrangement used
on late engines. When the piston is positioned 5°
BTC, timing is correctly set if the distributor rotor
arm points to No. 1 terminal in the distributor
cap and the distributor points are just ready to
break. See Fig. 25. Timing may be altered by
loosening the distributor mounting clamp and
turning the distributor. Turn the distributor clock-
wise to advance the timing and counterclockwise
to retard the timing. Do not overtighten the
mounting clamp screw.
FIG, 27-TIMING MARKS (Late Engines)
C-11. Check Ignition Wires and Connections
Examine and clean the insulation on all ignition
wires and check all connections. Cables should be
free from roughness, firm, flexible, and free from
minute cracks. Bend wires to check for brittle,
cracked, or loose insulation. Because defective
insulation will permit cross-firing or missing of the
engine, defective wires should be replaced.
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C-12. Service Air Cleaner
Clean and refill the air cleaner, See Par. B- 2 3 .
C-13. Check Fuel Line and Screens
Check all fuel line connections to guard against
leakage. Clean the fuel filtering screen and fuel
pump bowl.
C-14. Check Fuel Pump
The fuel pump should be checked for pressure,
volume, and vacuum as follows:
a. Fuel pump pressure is important, for low
pressure will seriously affect engine operation and
high pressure will cause excessive fuel consumption
and possibly flood the carburetor. Should there be
any doubt of normal operation, check the pressure
with a gauge as shown in Fig. 28.
The minimum and maximum allowable pressures
are 2 72 to 3% lb. [0,176 a 0,264 kg-cm2].
Also check the condition of the vacuum line r11bber
connector.
FIG. 28-CHECKING FUEL PUMP PRESSURE
b. Test for volume as a pump may build up
sufficient pressure but fail to produce sufficient
volume. Turn down the carburetor line fitting and,
with the tank line connected, pump out a couple
of strokes to be sure the pump is primed. Using
a half-pint bottle or similar measure, pump 72
pint [0,24 It.] of fuel by cranking the engine with
the starter motor. Count the strokes necessary to
fill the measure. If more than 20 strokes are re-
quired, the fuel pump is inefficient, the tank line
is
leaking air, or the fuel supply is restricted.