Jeep UNIVERSAL CJ-2A - Page 22

'Jeep' UNIVERSAL artd 'Jeep' DISPATCHER
c
a. When pressure quickly comes up to specified
pressure and is uniform between all cylinc:l.ers with- .
in 10 psi. [0,7 kg-cm2] it indicates that the e.'1gine
is operating normally with satisfactory seating of
rings, valves, valve timing, etc.
b. When pressure is low on the first stroke and
builds up to less than specified pressure it indicates
compression leakage usually attributable to rings
or valves. To determine which is responsible, pour
Y2 oz. [15 cm3] of tune-up oil into each cylinder.
Allow a few minutes for the oil to leak down past
the rings and then again test compression. If com-
pression pressures improve. over the first test, the
trouble is probably worn piston rings and bores. If
compression pressures do not improve, the trouble
is probably caused by improper valve seating. If
this condition is noticed on only two cylinders
that are adjacent, it indicates that there is a pos-
sible
gasket leak between these cylinders. If in-
spection of the spark plugs from these cylinders
disclosed fouling or surface cracking of electrodes,
gasket leakage is probable. ·
c. When pressure is higher than normal it indicates
that carbon deposits in the combustion chamber
have reduced the side of the chamber enough to
give the effect of a raised compression ratio. This
will usually cause pinging under load that cannot
be satisfactorily corrected by timing. The carbon
must be cleaned out of the engine to correct this
trouble.
d. Reinstall the spark plugs. Torque with a wrench
to proper setting.
Advise the vehicle owner if compression is not
satisfactory.
C-8. Check Valve Tappet Clearance
Adjust all valves with the engine cold.
a. For the four-cylinder L-head engine adjust
both intake and exhaust valves to .016" [0,406
mm.]. There is one exception. Rotor-type exhaust
valves were never installed on this engine in pro-
duction. The necessary parts for this installation,
however, are supplied in a kit so some L-head
engines may be so equipped. Where rotorctype
exhaust valves are installed, follow the specifica-
tions given in step b for F -head engines.
b. For the four-cylinder F -head engine adjust the
intake valves to .018" [0,46 mni.] clearance and the
exhaust valves to .016" [0,406 mm.] clearance.
C-9. Check Distributor
Refer to Fig. 25
a. The dstributor cap should be inspected for
cracks, carbon runners and evidence of arcing. If
any of these conditions exists, the cap should be
replaced. Clean any corroded high tension terminals.
b. Inspect the rotor for cracks or evidence of
excessive burning at the end of the metal strip.
After a distributor rotor has had normal use the
end of the rotor will become burned. If burning is
found on top of the rotor it indicates the rotor is
too short and needs replacing. Usually when this
condition is found the distributor cap segment will
be burned on the horizontal face and the cap will
also
need replacing.
c. Check the condenser lead for broken.' wires or
frayed insulation. Clean and tighten .the connections
on the terminal posts. Be sure the condenser is
mounted firmly on the distributor for a· good
ground connectl.on. . .
Should a conden.ser tester be avaiiable the ·capacity
should check from .21 to .25 microfarads: In the
absence of a tester check by substituting a new
condenser.
d. Examine the· distributor points. If they show
wear, poor mating, transferred metal, or pitting,.
then new aries should be installed. Clean the points
with a suitable solvent and a stiff bristled brush.
e. Check the alignment of the·. point for a full,
square contact .. If not correctly aligned, bend the
stationary contact bracket slightly to provide
alignment.
FIG. 25-DISTRIBUTOR
!-Condenser
2-Lubricating Wick
3-Breaker Arm Pivot
4-Breaker Cam
5-Distributor Points
6-0iler
7--·Adjustment Lock Screw
8-Adjusting Eccentric Screw
f. The contact gap should be set at .020" [0,508
mm.], measured with a wire gauge. Adjustment of
the gap is accomplished by loosening the lock
screw and turning adjusting eccentric screw
until correct gap is secured. Be sure that the
fiber block on the breaker arm is resting on the
highest point on the cam while the adjustment is
being made. Recheck the gap after locking the
adjustment.
g. Apply a thin film of cam lubricant to the cam
to lessen fiber block wear.
h. Check point contact spring pressure, which
should be between 17 and 20 ounces [0,487 a 0,56
kg.]. Check with a spring scale hooked on the
breaker arm at the contact and pull at right angle
to the breaker arm. Make the reading just as the
points separate. Adjust the point pressure by
loosening the stud holding the end of the contact
arm spring and slide the end of the spring in or out
as necessary. Retighten the stud and recheck the
pressure. Too low a pressure will cause engine
missing at high speeds. Too high ·a pressure will
cause rapid wear of the cam, block, and points.
C-10. Check Ignition Timing
If a neon timing light is available, use it to check
ignition timing following the instructions of the
timing light manufacturer.
In the absence of a timing light, remove No. 1
21