Hesitation, Sag, Stumble

Definition: Momentary 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.

^ Check fuel pressure. See CHART A-7. Also Check for water contaminated fuel.

^ Check for air leaks at air duct between Mass Air Flow (MAF) Sensor and throttle body.

^ Check for fouled Spark plugs.

^ Check for correct PROM number. Also check Service Bulletins for latest PROM.

^ Check Throttle Position Sensor (TPS) for binding or sticking.

^ Check ignition timing. See Emission Control Information label.

^ Check generator output voltage. Repair if less than 9 or more than 16 volts.

^ Check for open HEI ground, circuit 453.

^ Check canister purge system for proper operation.

^ Check EGR valve operation CHART C-7 or C-7A.