Hesitation, Sag, Stumble

DEFINITION: Momentary lack of response as the accelerator is pushed down. Can occur at all car speeds. Usually most severe when driving away from a stand still. May cause the engine to stall if severe enough.

^ See FLOW OF DIAGNOSIS.
^ Visually (physically) check
- Vacuum hoses for splits, kinks or improper connections.
- Ignition wires for cracking, hardness, or improper connections, at both distributor and spark plugs.
- Wiring for improper connections, pinches or cuts.
^ Make sure hot air tube is connected to air cleaner.
^ Check for proper operation of TCA.
NOTE: Cold engine only - check the following for sticking or faulty operation:
- Carburetor choke, including vacuum break, throttle linkage and fast idle cam.
- All choke adjustments, including vacuum breaks.
^ Check float level using external float gauge.
^ Check carburetor accelerator pump operation.
^ Check vacuum hose to Manifold Absolute Pressure (MAP) sensor for leaks, restrictions, and proper connections (should have full manifold vacuum).
^ Check EGR valve operation.
^ Check TPS adjustment. Use "Scan" tool if available.
^ Check canister purge system for proper operation.
^ Check for open ignition coil ground and for intermittent ECM ground.
^ Check engine timing. See Vehicle Emission Control information label.
^ Poor or contaminated gasoline. Check for excessive alcohol content. Suggest owner try different brand.