Surge, Hesitation, Stall on Acceleration

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

EGR malfunction Check EGR system in TESTING
flange gasket leaking, PROCEDURES
excessive backpressure,
loose valve

Spark timing Check Spark Controls in
COMPUTERIZED ENGINE CONTROLS

Faulty canister purge Check Evaporative system in
liquid fuel in carbon canister TESTING PROCEDURES

Ignition timing Check Ignition Timing in ADJUSTMENT
PROCEDURES

Restricted exhaust system Check Catalytic Converter system in TESTING PROCEDURES

Poor or contaminated fuel Recommend higher grade fuel