Surge, Hesitation, Stall on Deceleration

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. Refer to TESTING PROCEDURES.
flange gasket leaking,
excessive backpressure,
loose valve



Spark timing Check Spark Controls. Refer to COMPUTERS AND CONTROL SYSTEMS.



Air management valves Check Air Injection system. Refer to TESTING PROCEDURES.



Faulty canister purge Check Evaporative system. Refer to TESTING PROCEDURES.
Liquid fuel in carbon canister



Ignition timing Refer to COMPUTERS AND CONTROL SYSTEMS.



Restricted exhaust system Check Catalytic Converter. Refer to TESTING PROCEDURES.



Poor or contaminated fuel Recommend higher grade fuel. Refer to SPECIFICATIONS.