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 air cleaner assembly (clogged filter, restricted air inlet tube, etc.).
• Check EGR valve and solenoid for correct operation.
• Check for fouled spark plugs.
• Ensure ECM controlled idle speed is correct.
• Check distributor primary terminals for wear or corrosion.
• Check fuel injector(s) wire harness connector.
• Check throttle position sensor/switch for sticking or misadjustment.
• Check Manifold Air Temperature (MAT) sensor operation.
• Check coolant temperature sensor operation.
• Check pressure sensor operation.
• Ensure fuel system pressure is correct at all ranges.
• Check charging system output. Repair charging system if voltage is not between 9-16 volts.
• Use ohmmeter to verify correct fuel injector resistance.
• Check canister purge system for proper operation.
• Check initial ignition timing and spark advance system.
• Check for faulty ECM.