Fast Idle Speed

1985 Buick Century V6-231 3.8LSECTION Fast Idle Speed

CARBURETED MODELS

Refer to Tune Up Specifications chart for curb and fast idle speeds. Check and, if necessary, adjust engine idle speeds every 30,000 miles.

Check and, if necessary, adjust ignition timing before adjusting fast idle speed.
Make all adjustments with engine at normal operating temperature, choke fully open, air cleaner installed and A/C control Off, if equipped.
1. Disconnect and plug vacuum hoses as directed on vehicle emissions label.
2. Position fast idle speed screw on specified step of fast idle cam as directed on emissions label, then start engine.
3. Turn fast idle screw inward or outward and adjust fast idle speed to specifications.

FUEL INJECTED MODELS

Fast idle speed is controlled by the ECM and is not adjustable.



RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.