Code Interpretation And Diagnosis - Jeep 1987 Wrangler Workshop Manual

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THROTTLE BODY FUEL INJECTION SYSTEM
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1.4L 1983-1985
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CODE INTERPRETATION AND DIAGNOSIS
The chart below contains a list of troubles, possible
causes and suggested corrections.
TROUBLE
CODE/CONDITION
EE
S.
N
0
T
E
S
CODE 1 (unsatisfactory low air
temp, engine performance).
CODE 2 (unsatisfactory warm
temp, engine performance-
engine lacks power).
CODE 3 (unsatisfactory fuel
economy, hard cold engine
starting, stalling, and rough
idle).
CODE 4 (unsatisfactory engine
acceleration, sluggish per-
formance, unsatisfactory fuel
economy).
CODE 5 (unsatisfactory
acceleration, sluggish
performance).
CODE 6 (unsatisfactory fuel
economy, bad driveability, un-
satisfactory idle, black smoke
from tailpipe).
POSSIBLE CAUSE
Manifold air/fuel temperature
(MAT) sensor resistance is not
less than 1000 ohms (HOT) or
more than 100 kohms (VERY
COLD).
Coolant temperature sensor
resistance is less than 300 ohms
or more than 300 kohms (10
kohms at room temp.).
Defective wide open throttle
(WOT) switch or closed (idle)
throttle switch or both, and/or
associated wire harness.
Simultaneous closed throttle
switch and manifold absolute
pressure (MAP) sensor failure.
Simultaneous WOT switch and
manifold absolute pressure
(MAP) sensor failure.
Inoperative oxygen sensor.
CORRECTION
Replace the MAT sensor if not
within specifications. Refer to
the MAT sensor test procedure.
Replace the coolant temperature
sensor. Test the MAT sensor.
Refer to the coolant temp, sensor
test and MAT sensor test
procedures.
Test WOT switch operation and
the associated circuit. Refer to
the WOT switch test procedure.
Test closed throttle switch
operation and the associated
circuit. Refer to the closed
throttle switch test procedure.
Test the closed throttle switch
and repair/replace as necessary.
Refer to the closed throttle
switch test procedure.
Test the MAP sensor and
associated hoses and wire
harness. Repair or replace as
necessary. Refer to the MAP
sensor test procedure.
Test the WOT switch and repair
or replace as necessary. Refer to
the WOT switch test procedure.
Test the MAP sensor and
associated hoses and wire
harness. Repair or replace as
necessary. Refer to the MAP
sensor test procedure.
Test oxygen sensor operation
and replace if necessary. Test
the fuel system for correct
pressure. Test the EGR solenoid
control. Test the canister purge.
Test the secondary ignition
circuit. Test the PCV circuit.
Refer to the individual
component test procedure.
85430A
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