The idle fuel mixture adjustment is only necessary if % CO is found to be outside the specified range. It must only be made by adjusting differential pressure regulator current, and only after confirming that ignition timing and idle speed are within specifications. See IGNITION and 6.3 Idle Speed. For information on measuring differential pressure regulator current see 6.1 Air Flow Measurement and Fuel Metering.

The requirements and test conditions for making idle mixture adjustments on these engines are the same as those for checking or, where possible, adjusting idle speed. They are described in detail in 6.3 Idle Speed. The specifications are listed in Table n.

Table n. Idle Specifications (CIS-E)