Service Diagnosis - Performance (Carbureted Models) - Jeep 1987 Wrangler Workshop Manual

E N G I N E S
GENERAL SERVICE AND DIAGNOSIS
Service Diagnosis - Performance (Carbureted Models)
Condition
Possible Cause
Correction
HARD STARTING
(ENGINE CRANKS
NORMALLY)
(1) Binding linkage, choke valve or
choke piston.
(2) Restricted choke vacuum diaphragm.
(1) Repair as necessary.
(2) Clean passages.
(3) Improper fuel level.
(3) Adjust float level.
(4) Dirty, worn or faulty needle valve
and seat.
(4) Repair as necessary.
(5) Float sticking. (5) Repair as necessary.
(6) Faulty fuel pump.
(6) Replace fuel pump.
(7) Incorrect choke cover adjustment. (7) Adjust choke cover.
(8) Inadequate choke unloader
adjustment.
(8) Adjust choke unloader.
(9) Faulty ignition coil. (9) Test and replace as necessary.
(10) Improper spark plug gap. (10) Adjust gap.
(11) Incorrect ignition timing.
(11) Adjust timing.
(12) Incorrect valve timing.
(12) Check valve timing: repair as
necessary.
ROUGH IDLE OR
STALLING
(1) Incorrect curb or fast idle speed.
(2) Incorrect ignition timing.
(1) Adjust curb or fast idle speed.
(2) Adjust timing to specification.
(3) Improper feedback system operation. (3) Refer to Feedback System
Diagnosis.
(4) Improper fast idle cam adjustment. (4) Adjust fast idle cam.
(5) Faulty EGR valve operation.
(5) Test EGR system and replace as
necessary.
(6) Faulty PCV valve air flow.
(6) Test PCV valve and replace as
necessary.
B-12
80652A-1