Hesitates or Stalls 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


Electrical misfires Check ignition system.
SEE Powertrain Management/Ignition System/Testing and Inspection/Oscilloscope Patterns and Waveforms.

Initial timing incorrect Check base timing.
SEE Ignition System/ ADJUSTMENT PROCEDURES.

Incorrect Spark Advance Check Spark Controls.
SEE Ignition System/ TIMING SPECIFICATIONS

Incorrect Air-Fuel mixture Check fuel pressure.
Check O2 sensor.
Perform injector balance test (MPI).

EGR malfunction Check EGR system.

Faulty canister purge Check Fuel Evaporative System.

Restricted exhaust system Check Catalytic Converter.

Dirty air filters Clean or replace

Poor or contaminated fuel Recommend higher grade fuel