Adjusting the idle speed and CO content of the Monomotronic injection system (Audi 100 C4)

These adjustments are unnecessary if there is an injection system, since this task is performed by the control unit. Only in case of doubt is the idle speed and CO content checked. The conditions for the check are as follows:

The engine must be warmed up.

All electrical consumers are switched off.

The ignition timing is adjusted correctly.

The nominal values are as follows:

• 800-100 rpm.
• 0.2-1.2% vol (measured on the CO₂ exhaust pipe).

If the measured values do not match the nominal values, you should check the vacuum hoses and the magnetic valve of the fuel evaporation system, and interrogate the self-diagnostic device.