Diamante V6-3.5L SOHC (2003)
Air/Fuel Mixture: Testing and Inspection
IDLE MIXTURE CHECK
1. Before inspection, set the vehicle to the following condition.
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Engine coolant temperature: 80 - 95°C (176 - 203°F)
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Lights and all accessories: OFF
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Transmission: Neutral (P range)
2. Check to be sure that the basic ignition timing is at the standard value
Standard value: 5° BTDC ± 3°
3. After turning the ignition switch to OFF, connect a tachometer, or connect the scan tool to the data link connector.
NOTE: For the procedures for setting the tachometer.
4. Start the engine and race it at an engine speed of 2,500 r/min for two minutes.
5. Connect a CO and HC tester.
6. Check the CO contents and the HC contents while the engine is idling.
Standard value:
CO contents: 0.5% or less
HC contents: 100 ppm or less
7. If the concentrations are outside the standard values, check the following items.
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Diagnostic output
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Closed loop control
(If closed loop control is being carried out normally, the heated oxygen sensor output signal will vary between 0 - 400 mV and 600 - 1,000
mV while the engine is idling.)
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Fuel pressure
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Injectors
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Ignition coil, spark plug cables, spark plugs
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Evaporative emission control system
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Compression pressure
NOTE: If the results of the checks for all items are normal but the CO and HC concentrations still exceed the standard values, replace the
three-way catalyst.
