Jeep 1987 Wrangler Workshop Manual page 512

ENGINES
Jill
FUEL FEEDBACK SYSTEMS
CONNECT JUMPER WIRE
BETWEEN COOLANT
TEMPERATURE SWITCH
CONNECTOR TERMINALS
(HARNESS SIDE) AND
RECHECK PIN 12 ON
DIAGNOSTIC CONNECTOR
D2 AND MCU CONNECTOR
PIN 20 FOR CLOSED
CIRCUIT
CONTINUED
F R O M P R E V I O U S
PAGE
YES
START ENGINE, REMOVE
THROTTLE FROM FAST
IDLE CAM POSITION AND
ALLOW ENGINE TO
RETURN TO NORMAL IDLE
SPEED. ADJUST IDLE IF
NECESSARY ACCORDING
TO IDLE SPEED
ADJUSTMENT
PROCEDURE, TURN
ENGINE OFF.
REPLACE COOLANT
SWITCH AND RETEST
REPAIR CONTINUITY
PROBLEM IN COOLANT
SWITCH CIRCUIT
ENSURE THAT
CONTINUITY ALSO
EXISTS AT MCU
CONNECTOR PIN 56
RECHECK
NO
OK
DISCONNECT VACUUM
SWITCH ASSEMBLY AND
PLACE JUMPER WIRE
BETWEEN PLUGS A AND C
OF VACUUM SWITCH
CONNECTOR (HARNESS
SIDE) AND RETEST
CONTINUITY BETWEEN
DIAGNOSTIC CONNECTOR
02 PIN 15 AND MCU
CONNECTOR PIN 20
YES
TEST CONTINUITY
BETWEEN DIAGNOSTIC
CONNECTOR D2 PIN 15 AND
MCU CONNECTOR PIN 20.
CHECK THAT PORTED
VACUUM IS AT SWITCH 2
(4 IN. HG SWITCH).
REMOVE VACUUM HOSE
FROM SWITCH 2 (4 IN.
HG SW) AND INSTALL
HAND VACUUM PUMP
INCREASE VACUUM TO 4
IN. HG WHILE TESTING
CONTINUITY BETWEEN
DIAGNOSTIC CONNECTOR
D2 PIN 15 AND MCU
CONNECTOR PIN 20
CONTINUITY SHOULD
EXIST
CONT' D .
CONT' D .
8 1 1 3 l D ( J i
B-278