Hesitation, Sag, Stumble

Engine hesitates or stumbles on acceleration, sometimes stalling. This condition can occur at any speed, but primarily from a stop. Vehicle may also experience a surge or rise and fall of engine speed at cruise or steady throttle.

POSSIBLE CAUSE ACTION


Spark timing Check Spark Controls (EST, ESC). Chart C-5 Electronic Spark Control (ESC) Check



Faulty canister purge Check Evaporative system.
liquid fuel in carbon canister Refer to EMISSION CONTROL DEVICES/DIAGNOSIS, TESTING AND INSPECTION PROCEDURES/TESTING PROCEDURES/EVAPORATIVE EMISSION CONTROL SYSTEM



Restricted exhaust system Check Catalytic Converter
Refer to EMISSION CONTROL DEVICES/DIAGNOSIS, TESTING AND INSPECTION PROCEDURES/TESTING PROCEDURES/CATALYTIC CONVERTER



Poor or contaminated fuel Recommend higher grade fuel