1993 Volvo 850 AutomaticFACTORY OEM SERVICE PROCEDURE

Idle Speed & Ignition Timing

If adjustable, ensure idle speed and ignition timing are set to specification. Refer to the appropriate IDLE SPEED & CO LEVELΒ  and IGNITION TIMINGΒ  tables . For idle speed adjustment procedures, refer to the ADJUSTMENTS article. Ignition timing is not adjustable.

IDLE SPEED & CO LEVEL

Application Idle RPM (1) % CO Level
Cooling Fan On 800 0.6
Cooling Fan Off 825 0.6
(1) With O2 sensor disconnected. CO level is measured before catalytic converter.
IGNITION TIMING (Degrees BTDC @ RPM)

Application (1) Timing
850 10 @ 800
(1) Ignition timing is computer-controlled and is not adjustable.
Factory Service Tools

Use the Manual With the Right Hardware

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When to See a Mechanic

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

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

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