Express 1/2 Ton Van V8-305 5.0L VIN M SFI (1998)
Idle Speed: Testing and Inspection
IDLE SPEED
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When there is a problem with the idle refer to Idle Air Control System Diagnosis. See: Powertrain Management/Computers and Control
Systems/Testing and Inspection
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System too lean (High air/fuel ratio)-Idle speed may be too high or too low. Engine speed may vary up and down, disconnecting the IAC valve
has no effect.
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System too rich (Low air/fuel ratio)-idle speed too low. Scan counts usually above 80. System obviously rich and may exhibit black exhaust
smoke. Scan tool and/or voltmeter will read a Heated Oxygen Sensor (HO2S) signal fixed above 800 mV (0.8V).
