Hesitation, Sag Or Stumble

If there is a momentary lack of throttle response, which may occur at any speed, or is most severe when moving off from a stop, check the following items:

• Check EGR valve and solenoid operation.
• Check for fouled spark plugs or defective spark plug wires.
• Check for defective ignition wiring or connections.
• Ensure ignition timing and controls are working properly.
• Check throttle position sensor/switch for sticking or misadjustment.
• Check Manifold Air Temperature (MAT) sensor operation.
• Check charging system output. Repair charging system if voltage is not between 9 and 16 volts.
• Check fuel pressure.
• Check fuel for water contamination.
• Ensure correct ECM application. Check with dealer for latest application information.
• Check Manifold Absolute Pressure (MAP) sensor operation.
• Check canister purge operation.
• Check mass airflow sensor.
• Ensure engine warms to normal operating temperature.