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)



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