Hesitation, Sag, Stumble
DESCRIPTIONMomentary lack of response as the accelerator is pushed down. Can occur at all car speeds. Usually most severe when first trying to make the car move, as from a stop sign. May cause the engine to stall if severe enough. Perform careful visual check as described in When To Use This Section.
INSPECTION
^ Fuel pressure. Refer to Diagnostic Charts / A-Charts / Chart A-7. Also check for water contaminated fuel. Chart A-7 Fuel System Diagnosis
^ Spark plugs for being fouled or faulty wiring.
^ Mem-Cal number and Service Bulletins for latest Mem-Cal.
^ Throttle Position Sensor (TPS) for binding or sticking. Voltage should increase at a steady rate as throttle is moved toward wide open throttle.
^ Generator output voltage. Repair, if less than 9 or more than 16 volts.
^ Ignition system ground.
^ Canister purge system for proper operation. Refer to C-charts Component Testing / Chart C-3. Chart C-3 Canister Purge Check
^ Exhaust Gas Recirculation (EGR) Valve operation. Refer to C-charts Component Testing / Chart C-7. Chart C-7 Exhaust Gas Recirculation (EGR) Check
^ Check for Codes 33 and 34. (Manifold Absolute Pressure (MAP) sensor circuit.)
^ Perform "Injector Balance Test." Refer to C-charts Component Testing / Chart C-2A. Chart C-2A Injector Balance Test