Distributor; Distributor Rotor Inspection; Distributor Cap Inspection; Ignition System Timing - Jeep J-10 Series 1982 Technical & Service Manual

1A-18 GENERAL SERVICE AND DIAGNOSIS
when tested. If using an ignition coil tester (not an
ohmmeter) perform the tests according to the instruc
tions provided by the manufacturer of the equipment.
Refer to Chapter 1G—Ignition Systems for additional
information.
Distributor
The distributor used with all engines is a solid state,
electronically controlled type (i.e., no contact points).
Other than the cap and rotor inspection listed in the
Engine Maintenance Schedule, there is no scheduled
maintenance for distributors. Refer to Chapter
1G—Ignition Systems for distributor service
procedures.
DIstriluter Rotor tosptctiM
Visually inspect the rotor for cracks, evidence of cor
rosion and the effects of arcing on the metal tip, and
evidence of mechanical interference with the cap (fig.
1A-4). Some charring is normal on the end of the metal
tip. The silicone dielectric compoundapplied to the rotor
tip for radio interference noise suppression (six-and
eight-cylinder engines) will appear charred. This is nor
mal. Do not remove the charred compound. Test the
spring for insufficient tension. Replace a rotor that dis
plays any of the adverse conditions illustrated in figure
1A-4. Coat the tip of a replacement rotor (sue- and eight-
cylinder engines only) with Jeep Silicone Dielectric
Compound, or equivalent.
Distributor ftp tosptctioa
Remove the distributor cap and wipe clean with a dry
cloth. Perform a visual inspection for cracks, carbon
paths, broken towers, charred or eroded terminals and
ROTOR
TIP
CORRODED
INSUFFICIENT
SPRING
TENSION
EVIDENCE
OF
PHYSICAL
CONTACT
WITH
CAP
R|. 1A-4 Ptetofliiptetiofl
CRACKS
70202
damaged rotor button (fig. 1A-5). Replace any cap that
displays any of the adverse conditions illustrated in
figure 1A-5. When replacing a cap, transfer one spark
plug wire at a time to the replacement cap. If necessary,
refer to Distributor Wiring Sequence illustrated in Spec
ifications. Ensure each wire is installed in the tower
corresponding to its original tower position. Insert the
wire terminals firmly into the towers.
Replace the cap if the terminal ends inside the cap are
excessively eroded (fig. 1A-5). The vertical face of a
terminal end will indicate some evidence of erosion from
normal operation. Examine the terminal ends for evi
dence of mechanical interference with the rotor tip.
Ignition System Timing
A graduated timing degree scale located on the timing
case cover is used for timing each ignition system. An
index notch milled into the vibration damper is used to
reference the No. 1 cylinder ignition position of the
crankshaft with the correct timing mark on the gradu
ated scale (figs. 1A-6 and 1A-7).
RijBttlc Ttateg Prebi
A socket integral with the timing degree scale on the
timing case cover is provided for use with a special
magnetic timing probe that detects the milled notch in
the vibration damper. The probe is inserted through the
socket until it touches the vibration damper and is auto
matically spaced away from the damper by damper ec
centricity. Ignition timing is indicated on a meter or
computer printout, depending on the manufacturer's
equipment.
The socket is located at 9.5° ATDC, and the equipment
is calibrated to compensate for the degree difference. Do
not use the socket location when timing an ignition
system with a conventional timing light.
Igoltfoa Timing Proctdora
Refer to Tune-Up Specification charts and Emission
Control Information label located in the engine
compartment.
(1) Disconnect and plug distributor vacuum ad
vance hose opening.
(2) With ignition switch off, connect ignition timing
light and properly calibrated tachometer.
NOTE: If the timing light has an adjustable advance
control feature, turn the control to the OFFposition.
(3) For six-cylinder engines, disconnect two-wire
connector (yellow and black wires) at electronic ignition
module and short circuit ignition module connector ter
minals with jumper wire. This step does not apply to 49-
state designated CJ vehicles.
NOTE: When the ignition module connector terminals
are short circuited with the jumper wire the electronic
retard circuit is deactivated. This is necessary to accu
rately adjust the ignition timing.