Lack of Power/Sluggish/Spongy

Symptom: Engine delivers less than expected power. Little or no increase in speed when accelerator is pushed down part way.

POSSIBLE CAUSE ACTION

CHARGING SYSTEM MALFUNCTION - Check Battery voltage.

- Check Generator output voltage.

IGNITION SYSTEM MALFUNCTION - Scope check Ignition System. Check SECONDARY CIRCUIT firing Kv and spark duration.
SEE IGNITION SYSTEM/OSCILLOSCOPE PATTERNS.

- Remove spark plugs and inspect for: cracks, excessive wear, improper gap, burned electrodes, and wet or heavy deposits. Replace as necessary.


- Inspect spark plug wires for proper plug wire routing, crossfire between spark plugs or wires shorting to ground.

- Check IGNITION TIMING for excessive spark retard.
SEE IGNITION SYSTEM/ TIMING SPECIFICATIONS

ENGINE MECHANICAL MALFUNCTION - Check COMPRESSION. Perform a compression check, and cylinder leakage test, look for weak cylinders.

- Check for VACUUM LEAKS inspect Intake manifold, gasket(s), and hoses.

- Check exhaust system for leaks, restriction, or damage.

- Check valve timing, (timing belt alignment).

EMISSIONS COMPONENT MALFUNCTION - Check EGR valve for binding or sticking in the open position.

- Check EGR Transducer for proper operation.

- Check for plugged or contaminated Catalytic Converter.

FUEL SYSTEM MALFUNCTION - Check plugged or restricted Air Filter.

- Check fuel pressure.

- Check for lean Air-Fuel mixture, (O2S Sensor output).

- Perform injector balance test.

- Check fuel quality.

- Check Throttle Position Sensor for proper operation.

TRANSMISSION MALFUNCTION - Check for proper transmission shift points.

- Check for proper Torque Converter Clutch (TCC) operation, if applicable.