Excessive Odors

Symptom: Vehicle fails an emissions test or has an excessive "rotten egg" smell. Excessive odors do not necessarily indicate excessive emissions.

POSSIBLE CAUSES

Ignition System Malfunction

- Scope check Ignition System

- Check IGNITION COIL for proper output voltage.

- Check SPARK PLUGS for proper spark duration. Remove spark plugs, check for fuel fouled plugs, cracks, wear, improper gap, burned electrodes, or heavy deposits. Replace as necessary.

- Check SECONDARY CIRCUIT for abnormal firing Kv, crossfire between spark plugs (distributor cap, spark plug wires), and proper plug wire routing.

- Check IGNITION TIMING for excessive spark advance or retard.

Engine Mechanical Malfunction

- Check COMPRESSION Perform a compression check, and cylinder leakage test, look for sticking or leaking valves.

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

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

- Check for fuel contaminated oil in crankcase

Emissions Component Malfunction

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

- Check EGR Transducer for proper operation.

- Check for contaminated Catalytic Converter.

- Check EVAP Control system for proper operation.

Fuel System Malfunction

- Check for incorrect Air-Fuel mixture, O2 Sensor, perform injector balance test, inspect regulator operation (check vacuum line and return hose), check fuel pressure