Mercedes 280se 4.5, luft Leerlauf schraube/air idle screw adjustment

guten morgen,

kann mir bitte jemand helfen mit der Grund Einstellung der Luft Leerlauf schraube beim 280se 4.5?
Wo sollte sich diese schraube in der Einstellung befinden?

Vielen dank und grüsse aus west Canada

Sven

good morning,

I have a 280se 4.5. Can someone tell me where the air idle mixture screw should be in its basic adjustment?
And how is it adjusted, based on rpm only?

Much appreciated!
Sven

Hi Sven,
it's quite simple - the screw is adjusted so that the idle-rpm is correct.

When you have air-leaks somewhere in the system or maybe an defective AAV the idle runs out of the limits and cannot be adjusted by the screw anymore.

You have to check the TPS correctly sends the idle signal to the ECU.

Regards
Norbert 

Edit: Just noticed you talk about the 'air mixture screw'. There ist a grey plastic-knob screw at the ECU the idle mixture can be adjusted with. But this affects only the idle-mixture. The D-Jetronic-system doesn't have an 'air-mixture-screw' that's functional besides the idle. One could MISADJUST the MPS to change the mixture and USA-guys often like to do this - but this is not the way to solve problems.
The MPS is preadjusted in the factory for it's lifetime.
When the mixture isn't correct, you have to find the reason (...if not some guy has midadjusted the MPS before).

Hi Sven,

there is no base position of mixture screw. It has 22 clicks and u start from middle. But you need exhaust gas monitor to adjust properly.