Camshaft Position Sensor; Ignition Timing - Jeep 1997 Grand Cherokee Service Manual

ERODED CHARRED BROKEN TOWER CARBON PATH MINALS CRACK TER- OR
ZG
DIAGNOSIS AND TESTING (Continued)
Fig. 10 Cap Inspection—External—Typical
Fig. 11 Cap Inspection—Internal—Typical
on the end of the metal tip. The silicone-dielectric-
varnish-compound applied to the rotor tip for radio
interference noise suppression, will appear charred.
This is normal. Do not remove the charred com-
pound. Test the spring for insufficient tension.
Replace a rotor that displays any of these adverse
conditions.

IGNITION TIMING

NOTE: Base (initial) ignition timing is NOT adjust-
able on any 4.0L/5.2L/5.9L engine. Do not attempt to
adjust ignition timing by rotating the distributor.
NOTE: On 4.0L 6–cylinder engines, do not attempt
to modify the slotted fork on the distributor housing
to get distributor rotation. Distributor position will
have no effect on ignition timing.
All ignition timing functions are controlled by the
powertrain control module (PCM). For additional
AGED ROTOR BUT- WORN DISTRIBUTOR CARBON P ATH OR CAP DAM- TON ROTOR CORRODED
information, refer to the appropriate Powertrain
Diagnostics Procedures service manual for operation
of the DRB Scan Tool.
MAP SENSOR
For an operational description, diagnosis or remov-
al/ installation procedures, refer to Group 14, Fuel
Systems.
CRANKSHAFT POSITION SENSOR
To perform a complete test of this sensor and its
circuitry, refer to the DRB scan tool. Also refer to the
appropriate Powertrain Diagnostics Procedures man-
ual.

CAMSHAFT POSITION SENSOR

The camshaft position sensor is located in the dis-
tributor (Fig. 13) on all engines.
To perform a complete test of this sensor and its
circuitry, refer to the appropriate Powertrain Diag-
nostics Procedures service manual. To test the sensor
only, refer to the following:
For this test, an analog (non-digital) voltme-
ter is needed. Do not remove the distributor connec-
tor from the distributor. Using small paper clips,
insert them into the backside of the distributor wire
harness connector to make contact with the termi-
nals. Be sure that the connector is not damaged
when inserting the paper clips. Attach voltmeter
leads to these paper clips.
(1) Connect the positive (+) voltmeter lead into the
sensor output wire. This is at done the distributor
wire harness connector. For wire identification, refer
to Group 8W, Wiring Diagrams.
TIP SPRING INSUFFICIENT PHYSICAL CONTACT EVIDENCE SION TEN- WITH CAP OF
IGNITION SYSTEM
Fig. 12 Rotor Inspection—Typical
CRACKS
8D - 7