High HC & CO - at High RPM

This condition is indicated by abnormally high carbon monoxide AND hydrocarbon emissions during cruise (2500 rpm).

POSSIBLE CAUSE ACTION


Electrical misfires Check ignition system



Vacuum leak Check vacuum lines and routing in
"Vacuum and Vapor Hose Routing"
in Emissions - Check intake manifold
and vacuum components



Faulty bowl vent/canister purge system Check Evaporative System in
"Testing Procedures" in Emissions



PCV malfunction Check PCV system in "Testing
Procedures" in Emissions



Restricted exhaust Check Catalytic Converter in
"Testing Procedures" in Emissions



Initial timing incorrect Check Ignition Timing in "Adjustment
Procedures" in Emissions



Incorrect Spark Advance Check Spark Controls in
"Fuel Injection and Computerized
Engine Controls"



Fuel metering malfunction Check fuel pressure
Perform injector balance test
Test regulator operation
(check vacuum line and return hose),
Service Fuel Injectors (pressure clean)