Surge, Hesitation, Stall on Acceleration

SYMPTOM:
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" in Emissions
excessive backpressure,
loose valve


Spark timing Check Spark Controls in
"Fuel Injection and Computerized
Engine Controls"


Air management valves Check Air Injection system in
"Testing Procedures" in Emissions


Hot air tube not connected Check inlet air temperature system (TAC)
to air cleaner, vacuum motor in "Testing Procedures" in Emissions
inoperative, air damper
door binding or not opening


Faulty canister purge Check Evaporative system in
liquid fuel in carbon canister "Testing Procedures" in Emissions


Ignition timing Check Ignition Timing in "Adjustment
Procedures" in Emissions


Restricted exhaust system Check Catalytic Converter system in
"Testing Procedure" in Emissions


Poor or contaminated fuel Recommend higher grade fuel