DRIVEABILITV AND EMISSIONS 6E2-145
CHART C-40-2
ELECTRONIC IGNITION (EI) MISFIRE UNDER LOAD
CD • IF ENGINE MISFIRES AT IDLE ONLY, SEE CHART C-4D-1. • IGNITION "OFF"
• DISCONNECT ONE SPARK PLUG LEAD AT A TIME AND,
INSTALL SPARK TESTER (ST-125) J-26792 OR EQUIVALENT.
• OBSERVE SPARK TESTER WITH ENGINE IDLING. REPEAT THIS TEST FOR ALL PLUG LEADS. SEE CAUTION* • SPARK SHOULD JUMP TESTER GAP ON ALL LEADS, WITH
ENGINE IDLING, DID IT?
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• WITH IGNITION "OFF", GROUND THE OPPOSITE PLUG CHECK FOR: LEAD OF THE AFFECTED COIL AT SPARK PLUG. -
FAUL TV, WORN OR CRACKED SPARK PLUG(S). • SPARK SHOULD JUMP TESTER GAP WHILE CRANKING -PLUG FOULING DUE TO ENGINE MECHANICAL FAULT. ENGINE. DOES IT? IF SPARK PLUGS CHECK OUT OK, SEE "CUTS OUT,
MISSES" IN SYMPTOMS SEe'l'tO'I'Q' "B".
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• CHECK THE RESISTANCE OF EACH PLUG WIRE OF THE COIL REPLACE THE SPARK PLUG FOR THE LEAD WHICH
WHICH DID NOT FIRE THE SPARK TESTER. WAS JUMPERED TO GROUND. IF MISFIRE IS STILL
• WIRE RESISTANCE SHOULD BE LESS THAN 30,000 OHMS EACH PRESENT, START MISFIRE TEST AGAIN AT STEP 1. AND WIRES SHOULD NOT BE GROUNDED. ARE WIRES OK?
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• REMOVE COIL RETAINING NUTS AND REMOVE COILS. REPLACE FAUL TV WIRE(S). I ® • COILS SHOULD BE FREE OF CARBON TRACKING. ARE THEY?
$ $
• SWITCH A NORMALLY OPERATING COIL WITH REPLACE IGNITION COIL. ALSO CHECK FOR THE COIL FROM PROBLEM CYLINDER. FAUL TV PLUG WIRE CONNECTION(S) AND • SPARK SHOULD JUMP TESTER GAP WITH WIRE
NIPPLE(S) FOR CARBON TRACKING.
ENGINE IDLING. DID IT?
:r ~ ORIGINAL IGNITION
I
REPLACE ELECTRONIC IGNITION MODULE. COIL IS FAUL TV.
*CAUTION: When handling secondary spark plug leads with engine running, insulated pliers must be used and care exercised to prevent a possible electrical shock.
CLEAR
DIAGNOSTIC TROUBLE CODES AND CONFIRM "CLOSED LOOP" OPERATION AND NORMAL "CHECK ENGINE" MALFUNCTION
INDICATOR LAMP OPERATION.
