High HC & CO - at High RPM

Condition: High Carbon Monoxide and Hydrocarbons during cruise (2500 rpm).


POSSIBLE CAUSE ACTION



Electrical misfires ^ Check ignition system.

^ SEE IGNITION SYSTEM/ OSCILLOSCOPE PATTERNS.


Initial timing incorrect ^ Check base timing.

^ SEE IGNITION SYSTEM/ ADJUSTMENT PROCEDURES.


Incorrect Spark Advance ^ Check Spark Controls.

^ SEE IGNITION SYSTEM/ TIMING SPECIFICATIONS


Vacuum leak ^ Check vacuum lines and routing.

^ SEE Vehicle Emission Control Information (VECI) label under hood.

^ Check intake manifold and vacuum components.


Faulty canister purge system ^ Check Fuel Evaporative System.


Restricted exhaust ^ Check Catalytic Converter.


[1][2]PCV malfunction ^ Check PCV system.


Fuel Injection malfunction ^ Check fuel pressure.

^ Perform injector balance test.

^ Service Fuel Injectors (Pressure cleaner).