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Test 18 - Co & Idle Speed Adjustment

  1. Idle speed is adjusted on the throttle housing with terminals "B" and "C" bridged at test plug. CO level is adjusted on the hot wire air sensor with Adjuster Tool (9230).
  2. The adjusting values should be at an idle speed of 660-700 RPM (check value 640-720 RPM). With oxygen sensor disconnected, the CO level should be .4-.8%. All electric equipment must be turned off. Ensure engine is running at operating temperature for CO and idle speed adjustment.
  3. When adjusting the idle speed it is important that the engine speed does not drop below 640 RPM, since then idle speed stabilization would occur and the ignition timing would be misadjusted up to 22° BTDC.
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