Jeep Cherokee 2000 Service Manual - page 364
(b) Remove cylinder number 1 spark plug.
(c) Hold a finger over the open spark plug hole.
Rotate engine at vibration dampener bolt until
compression (pressure) is felt.
(d) Slowly continue to rotate engine. Do this
until timing index mark on vibration damper pul-
ley aligns with top dead center (TDC) mark (0
degree) on timing degree scale (Fig. 31). Always
rotate engine in direction of normal rotation. Do
not rotate engine backward to align timing marks.
(e) Install oil pump drive into engine while
aligning into slot on oil pump. If pump drive will
not drop down flush to engine block, the oil pump
slot is not aligned. Remove oil pump drive and
align slot in oil pump to shaft at bottom of drive.
Install into engine. Rotate oil pump drive back to
its original position and install hold-down clamp
and bolt. Finger tighten bolt. Do not do a final
tightening of bolt at this time.
(f) Remove toothpick from housing.
(6) Install sensor to oil pump drive. After installa-
tion, the CMP sensor should face rear of engine 0°.
(7) Install 2 sensor mounting bolts and tighten to
2 N·m (15 in. lbs.) torque.
(8) Connect electrical connector to CMP sensor.
(9) If removed, install spark plug and ignition coil
rail.
To verify correct rotational position of oil pump
drive, the DRB scan tool must be used.
WARNING: WHEN PERFORMING THE FOLLOWING
TEST, THE ENGINE WILL BE RUNNING. BE CARE-
FUL NOT TO STAND IN LINE WITH THE FAN
BLADES OR FAN BELT. DO NOT WEAR LOOSE
CLOTHING.
(10) Connect DRB scan tool to data link connector.
The data link connector is located in passenger com-
partment, below and to left of steering column.
(11) Gain access to SET SYNC screen on DRB.
(12) Follow directions on DRB screen and start
engine. Bring to operating temperature (engine must
be in “closed loop” mode).
(13) With engine running at idle speed, the words
IN RANGE should appear on screen along with 0°.
This indicates correct position of oil pump drive.
(14) If a plus (+) or a minus (-) is displayed next to
degree number, and/or the degree displayed is not
zero, loosen but do not remove hold-down clamp bolt.
Rotate oil pump drive until IN RANGE appears on
screen. Continue to rotate oil pump drive until
achieving as close to 0° as possible.
The degree scale on SET SYNC screen of DRB is
referring to fuel synchronization only. It is not
referring to ignition timing. Because of this, do
not attempt to adjust ignition timing using this
method. Rotating oil pump drive will have no effect
on ignition timing. All ignition timing values are con-
trolled by powertrain control module (PCM).
(15) Tighten hold-down clamp bolt to 23 N·m (17
ft. lbs.) torque.
DISTRIBUTOR—2.5L ENGINE
The distributor contains an internal oil seal that
prevents oil from entering the distributor housing.
The seal is not serviceable.
Factory replacement distributors are equipped with
a plastic alignment pin already installed. The pin is
located in an access hole on the bottom of the distrib-
utor housing (Fig. 32). It is used to temporarily lock
the rotor to the cylinder number 1 position during
installation. The pin must be removed after install-
ing the distributor.
The camshaft position sensor is located in the dis-
tributor (Fig. 33). For removal/installation proce-
dures, refer to Camshaft Position Sensor. Distributor
removal is not necessary for sensor removal.
Refer to (Fig. 33) for an exploded view of the dis-
tributor.
A fork with a slot is supplied on the bottom of the
distributor housing where the housing base seats
against the engine block (Fig. 33). The centerline of
the slot aligns with the distributor holddown bolt
hole in the engine block. Because of the fork, the dis-
tributor cannot be rotated. Distributor rotation is not
necessary as all ignition timing requirements are
handled by the Powertrain Control Module (PCM).
The position of the distributor determines fuel syn-
chronization only. It does not determine ignition tim-
ing.
Fig. 32 Plastic Alignment Pin—2.5L Engine
1 – PLASTIC ALIGNMENT PIN
XJ
IGNITION SYSTEM
8D - 17
REMOVAL AND INSTALLATION (Continued)