Distributor Replacement - Jeep 1979 CJ-5 Technical & Service Manual

(3) Repeat for negative wire.
(4) Connect ammeter between positive terminal and
disconnected positive wire.
(5) Connect jumper wire from coil negative termi-
nal to known good ground.
(6) Turn ignition to On position.
(7) Amperage should read approximately 7 amps,
and should not exceed 7.6 amps.
(8) If current flow is more than 7.6 amps, replace
coil.
(9) Leave ammeter connected to coil positive termi-
nal. Remove jumper wire from negative terminal. Con-
nect coil green wire to negative terminal. Current flow
should be approximately 4 amps.
If current flow is less than 3.5 amps, check for poor
connections in 4-wire and 3-wire connectors or poor
ground at ground screw inside distributor. If currect
flow is greater than 5 amps, the control unit is defective.
(10) Start engine. Normal current flow with engine
running is 2.0 to 2.4 amps.
If current flow is outside specifications, the control unit
is defective.
Coif Output Test
(1) Connect oscilloscope to engine.
(2) Start engine and observe secondary spark
voltage.
(3) Remove one spark plug wire from distributor
cap. Observe voltage on oscilloscope corresponding to
discpnnected plug wire. This voltage, referred to as open
circuit voltage, should be 24,000 volts (24 KV) minimum.
CAUTION: Do not remove wires from plugs in cylin-
ders 3 or 5 of a six-cylinder engine or cylinders 3 or 4 of
an eight-cylinder engine when performing this test, or
sensor may be damaged.
CAUTION: Do not operate engine with spark plug dis-
connected for more than 30 seconds or catalytic con-
verter may be damaged.
OiSTliBUTOl IEPLICE1ENT
Removal
(1) Unfasten distributor cap retaining screws. Re-
move distributor cap with high tension cables and posi-
tion aside.
(2) Disconnect vacuum hose from distributor vac-
uum advance unit.
(3) Disconnect d i s t r i b u t o r p r i m a r y w i r i n g
connector.
IGNITION SYSTEM 1G-15
(4) Scribe mark on distributor housing in line with
tip of rotor. Scribe mark on distributor housing near
clamp and scribe matching mark on engine. Note posi-
tion of rotor and distributor housing in relation to sur-
rounding engine parts as reference points for installing
distributor.
(5) Remove distributor holddown screw and clamp.
(6) Withdraw distributor carefully from engine.
installation
(1) Clean distributor mounting area of engine block.
(2) Install replacement distributor mounting gasket
in counterbore of engine.
(3) Position distributor in engine. If engine was not
rotated while distributor was removed, perform the
following:
(a) Align rotor tip with mark scribed on distrib-
utor housing during removal. Turn rotor approximately
1/8-turn counterclockwise past scribed mark.
(b) Slide distributor down into engine. Align
scribe mark on distributor with matching scribe mark
on engine.
NOTE: It may be necessary to move rotor and shaft
slightly to start gear into mesh with camshaft gear and
to engage oil pump drive tang, but rotor should align
with scribed mark when distributor is down in place.
(c) Install distributor holddown clamp, screw
and lockwasher, but do not tighten screw.
(4) If engine was rotated while distributor was re-
moved, it will be necessary to establish timing as
follows:
(a) Remove No. 1 spark plug. Hold finger over-
spark plug hole and rotate engine until compression
pressure is felt. Slowly continue to rotate engine until
timing mark on crankshaft pulley lines up with top dead
center (0) mark on timing quadrant. Always rotate en-
gine in direction of normal rotation. Do not turn engine
backward to align timing marks.
(b) Turn distributor shaft until rotor tip points
in the direction of the No. 1 terminal in the distributor
cap. Turn rotor 1/8-turn counterclockwise past the posi-
tion of the No. 1 terminal.
(c) Slide distributor down into er..lie and posi-
tion distributor vacuum advance housing in approx-
imately the same location (in relation to surrounding
engine parts) as when removed. Align scribe mark on
distributor with matching scribe mark on engine.
NOTE: It may be necessary to rotate the oil pump
shaft with a long flat-blade screwdriver to engage oil
pump drive tang, but rotor should align with the posi-
tion of No. 1 terminal when distributor is down in place.