Hesitation/Sag/Stumble

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

NOTE: This symptom may be cause by an accumulation of intake valve deposits and/or clogged fuel injectors. Refer to the TSB for further information.

Vacuum Hoses
- Vacuum hoses for splits, kinks, and proper connections as shown on vehicle emission control label vacuum diagram.

Engine Mechanical
- Air leaks at common chamber and intake manifold gaskets

Ignition Systems
- Ignition wires for cracks, burned spots or burned ends, hardening, correct firing order and proper resistance.
- Wiring harness for bare spots, pinches, cuts or corroded connections.
- Ignition timing.
- For open ignition system ground.

Fuel Systems
- Fuel pressure.
- Water contaminated fuel.
- TPS for binding or sticking.
- Air flow sensor.
- Clogged fuel injectors.

Emission Systems
- Canister purge system for proper operation.
- EGR valve operation.

Starting and Charging System
- Alternator output voltage.