# S14 idle adjustment

#### To adjust the idle speed, it is essential that the following requirements be met first :

| Engine at operating temperature, oil temp must be at least 60° C (140° F)
| All electrical items shut off.
| A/C switched off
| Air filter clean and free of obstruction
| CO correctly adjusted

Pull of throttle switch plug and bridge pins 2 and 18 in the plug to ensure a closed throttle signal to the Motronic Control Unit. |
Adjust the idle speed by turning the central air control screw until 880 rpm is reached |
Connect a manometer to each vacuum tap on the manifold. Use a 4 gauge setup if available. |
Take note of all four values, which must be in the range of 300 ± 50 mbar.
For proper intake vacuum synchronization, all single throttle plates have to be adjusted by turning the individual bypass screws (under yellow or blue caps) within ± 5 mbar of the average vacuum (add up all 4 values and divide by four, this will give the average vacuum). |
To adjust any given throttle, rotate adjusting screw until desired reading is obtained. |
Check idle speed again, and if necessary, adjust back to 880 ± 50 rpm by turning the central air control screw.

### Part Numbers

Anti tamper caps (blue) | : | 13 11 1 265 510
Vacuum caps | : | 11 61 1 437 560

E30 M3 Repair Manual V2.7. Copyright ©1999-2001 Koala Motorsport & Brett Anderson