HINT: This check is used only to determine whether or not the idle HC/CO 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 lines properly connected
HINT; All vacuum hoses for EGR systems, etc. should be properly connected.
(f) EFI system wiring connectors fully plugged
(g) Ignition timing set correctly
(h) Transmission in neutral
(i) Tachometer and HC/CO meter calibrated and at hand.
2. START ENGINE
3. RACE ENGINE AT 2,500 RPM FOR APPROX. 120 SECOUNDS
4. INSERT HC/CO METER TESTING PROBE INTO TAILPIPE AT LEAST 40 cm (1.3 ft)
5. CHECK HC/CO CONCENTRATION AT IDLE AND/OR 2,500 RPM
Complete the measuring within three minutes.
HINT: When performing the 2 mode (2,500 rpm and idle) test, follow the measurement order prescribed by the regulations.
If the HC/CO concentration at 2,500 rpm does not conform to regulations, try the following procedure.
Race the engine again at 2,500 rpm for approx. 1 minute and quickly repeat steps 4 and 5 above. This may correct the problem.
Idle and/or 2,500 rpm HC/CO ENGINE MECHANICAL - Concentration Check Method
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