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 1. Check the EGR system under TESTING
flange gasket leaking, PROCEDURES. If OK, step 2
excessive backpressure, 2. Check the EGR electronic controls. Refer to
loose valve COMPUTERIZED ENGINE CONTROLS.





Spark timing Check the Spark Controls (SCC).
Refer to COMPUTERIZED ENGINE CONTROLS.



Air management valves Check the Air Injection system under
TESTING PROCEDURES.





Hot air tube not connected Check the Inlet Air Temperature System
to air cleaner, vacuum motor under TESTING PROCEDURES.
inoperative, air damper
door binding or not opening



Faulty canister purge 1. Check the Evaporative system under
liquid fuel in charcoal canister TESTING PROCEDURES. If OK, step 2
2. Check the Evaporative System electronic controls.
Refer to COMPUTERIZED ENGINE CONTROLS.


Ignition timing Check the Ignition Timing under ADJUSTMENT
PROCEDURES.



Restricted exhaust system Check the Catalytic Converter
under TESTING PROCEDURES.



Poor or contaminated fuel Recommend higher grade fuel