Engine Coolant Temperature Sensor; Intake Manifold Air Temperature Sensor - Jeep Wrangler 1997 Manual

8D - 1 0
IGNITION SYSTEM
DIAGNOSIS AND TESTING (Continued)
DISTRIBUTOR
ASSEMBLY
Fig. 23 Camshaft Position Sensor-Typical
The movable pulse ring should now be within the
sensor pickup .
(5) Turn ignition key to ON position . Voltmeter
should read approximately 5.0 volts.
(6) If voltage is not present, check the voltmeter
leads for a good connection .
(7) If voltage is still not present, check for voltage
at the supply wire . For wire identification, refer to
Group 8W Wiring Diagrams .
(8) If 5 volts is not present at supply wire, check
for voltage at PCM 32-way connector (cavity A-17).
Refer to Group 8W Wiring for location of connector/
terminal . Leave the PCM connector connected for
this test .
(9) If voltage is still not present, perform vehicle
test using the DRB scan tool .
(10) If voltage is present at cavity A-17, but not at
the supply wire :
(a) Check continuity between the supply wire .
This is checked between the distributor connector
and cavity A-17 at the PCM. If continuity is not
present, repair the harness as necessary.
(b) Check for continuity between the camshaft
position sensor output wire and cavity A-18 at, the
PCM . If continuity is not present, repair the har-
ness as necessary.
(c) Check for continuity between the ground cir-
cuit wire at the distributor connector and ground .
If continuity is not present, repair the harness as
necessary .
(11) While
observing the voltmeter, crank the
engine with ignition switch . The voltmeter needle
should fluctuate between 0 and 5 volts while the
engine is cranking. This verifies that the camshaft
position sensor in the distributor is operating prop-
erly and a sync pulse signal is being generated.
If sync pulse signal is not present, replacement of
the camshaft position sensor is necessary
TJ
ENGINE COOLANT TEMPERATURE SENSOR
For an operational description,
diagnosis and
removal/installation procedures, refer to Group 14,
Fuel System.
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
For an operational description,
diagnosis and
removal/installation procedures, refer to Group 14,
Fuel System.
SPARK PLUG CABLES
Check the spark plug cable connections for good
contact at the coil(s), distributor cap towers, and
spark plugs. Terminals should be fully seated . The
insulators should be in good condition and should fit
tightly on the coil, distributor and spark plugs. Spark
plug cables with insulators that are cracked or torn
must be replaced .
Clean high voltage ignition cables with a cloth
moistened with a non-flammable solvent. Wipe the
cables dry. Check for brittle or cracked insulation .
TESTING
When testing secondary cables for damage with an
oscilloscope, follow the instructions of the equipment
manufacturer.
If an oscilloscope is not available, spark plug cables
may be tested as follows:
CAUTION: Do not leave any one spark plug cable dis-
connected for longer than necessary during testing .
This may cause possible heat damage to the catalytic
converter . Total test time must not exceed ten minutes .
With the engine running, remove spark plug cable
from spark plug (one at a time) and hold next to a
good engine ground . If the cable and spark plug are
in good condition, the engine rpm should drop and
the engine will run poorly. If engine rpm does not
drop, the cable and/or spark plug may not be operat-
ing properly and should be replaced . Also check
engine cylinder compression.
With the engine not running, connect one end of a
test probe to a good ground . Start the engine and run
the other end of the test probe along the entire length of
all spark plug cables . If cables are cracked or punc-
tured, there will be a noticeable spark jump from the
damaged area to the test probe. The cable running from
the ignition coil to the distributor cap can be checked in
the same manner. Cracked, damaged or faulty cables
should be replaced with resistance type cable. This can
be identified by the words ELECTRONIC SUPPRES-
SION printed on the cable jacket .
Use an ohmmeter to test for open circuits, excessive
resistance or loose terminals. Remove the distributor
cap from the distributor . Do not remove cables from
cap. Remove cable from spark plug. Connect ohmme-
ter to spark plug terminal end of cable and to corre-