Adjusting engine idle speed (BMW 3 Series E21)

Idle speed adjustment must be performed on a warm engine (oil temperature 60°C) with adjusted valve timing clearances and with the ignition timing set correctly.

Remove the air filter.

Install the 13 0 000 air filter simulator by connecting its hose to the air filter and cylinder head.

Using the mixture quantity adjusting screw 1 (see photo), set the proper engine idle speed.



Remove the threaded plugs from the exhaust manifolds and screw in sensors 13 0 020 instead.

Attach the gas analyzer and adjust the screws 2 (for rear exhaust manifold) and 3 (for front exhaust manifold) quality (composition) of the mixture to achieve the specified content of carbon monoxide (CO) in the exhaust gases.



After completing the adjustment, install new blue plastic plugs into the hole for the mixture quality adjustment screws 2 and 3.

[This article is based on information from the website «BMWMAN.ru»]