FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Component Tests and General Diagnostics

IDLE AND/OR 2,500 RPM CO/HC CHECK

HINT: This check is used only to determine whether or not the idle CO/HC complies with regulations.

1. INITIAL CONDITIONS:
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected-
(d) All accessories switched OFF
(e) All vacuum hoses (for EGR systems, etc.) properly connected.
(f) SFI system wiring connectors fully plugged
(g) Ignition timing set correctly
(h) Transmission in neutral range
(i) Tachometer and CO/HC meter, calibrated by hand

2. START ENGINE.
3. RACE ENGINE AT 2,500 RPM FOR APPROX. 180 SECONDS.



4. INSERT CO/HC METER TESTING PROBE AT LEAST 40 cm (1.3 ft) INTO TAILPIPE DURING IDLING.
5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT IDLE AND/OR 2,500 RPM.

HINT: When performing the 2 mode (2,500 rpm and idle) test, follow the measurement order prescribed by, the applicable local regulations.