Ignition System Troubleshooting Chart; Engine Will Not Start - Jeep J-10 Series 1982 Technical & Service Manual

Ignition System Troubleshooting Chart
ENGINE WILL NOT START
IGNITION SYSTEMS 1G-5
NOTE: IF A TACHOMETER IS CONNECTED TO THE TACHOMETER TERMINAL. DISCONNECT IT BEFORE PROCEED
ING WITH THE TEST.
I. CHECK SPARK AT PLUG WITH TOOL
J-26792 WHILE CRANKING ENGINE
(IF NO SPARK FROM FIRST WIRE,
CHECK SECOND WIRE).
I
I SPARK I
. !dLr
| CHECK FUEL. SPARK PLUGS. ETC.
NO SPARK
2. CHECK VOLTAGE AT IGNITION COIL B+
TERMINAL WHILE CRANKING ENGINE.
_r
LESS THAN 1 VOLT
REPLACE IGNITION COIL
SPARK
INSPECT CAP FOR
WATER. CRACK, ETC. IF
OK, REPLACE ROTOR.
NO DROP IN VOLTAGE
CHECK MODULE GROUND
AND FOR OPEN IN WIRES
FROM COIL TO
DISTRIBUTOR. IF OK.
REPLACE MODULE.
IF MODULE TESTER IS
AVAILABLE. TEST
MODULE.
m
DEFECTIVE
REPLACE
MODULE
CHECK IGN. COIL GROUND.
IF OK, REPLACE IGN. COIL
7 VOLTS OR MORE
3. WITH IGNITION "ON, "CHECK
TACH" TERMINAL VOLTAGE.
MORE THAN 10 VOLTS
CHECK FOR SPARK AT COIL
OUTPUT TERMINAL WITH TOOL
J-26792 WHILE CRANKING
ENGINE (VIEW A).
NO SPARK
REMOVE PICKUP COIL CONNECTOR
FROM MODULE. TURN IGNITION
SWITCH "ON". WITH HIGH INPUT
IMPEDANCE VOLTMETER, OBSERVE
VOLTAGE AT TACH" (-) TERMINAL
WHILE TEST LAMP IS MOMENTARILY
CONNECTED TO MODULE"P"
TERMINAL (NOT MORE THAN
5 SECONDS). VIEWB
1 VOLTAGE DROPS
UNDER 7 VOLTS
»
REPAIR PRIMARY WIRE CIRCUIT
TO IGNITION SWITCH.
| 1 TO 10 VOLTS I
REPLACE MODULE AND CHECK
FOR SPARK AS IN STEP 1 ABOVE.
SPARK
SYSTEM
OK
| NO SPARK
REPLACE IGN.
COIL. IT IS ALSO
DEFECTIVE.
6. CHECK FOR SPARK FROM COIL WITH
TOOL J-26792 AS TEST LAMP IS REMOVED
FROM MODULE "P" TERMINAL
NO SPARK
3
SPARK
IF NO MODULE TESTER IS AVAILABLE. 1 | REPLACE PICKUP COIL . |
7. CHECK IGN. COIL GROUND CIRCUIT. IF
OK. REPLACE IGN. COIL AND REPEAT
STEP 6.
SPARK
SYSTEM OK
NO SPARK I
COIL REMOVED IS OK, INSTALL ORIGINAL
COIL AND REPLACE MODULE.
NOTE: REFER TO VIEWS A AND B.
90832A