Idling Control On R129

[yiug412]

Hi guys

Does anyone know how i can adjust the idle speed on the R129 SL320?
the mechanics told me it cant be done as it's control by the ECU.

thanks

Louis

 

[stats007]

Idle speed control is electronic - what exactly is the problem?

Also depends on what year the car is.

 

[television]

As stats, all 129's are electronic

 

[yiug412]

As stats, all 129's are electronic

so there's no way i can tune the idle higher?

last time the engine stored doing a hill start.

 

[television]

what year is the car, and what model

 

[stats007]

No reason to 'tune' it. If it stalled there is a problem elsewhere.

 

[yiug412]

No reason to 'tune' it. If it stalled there is a problem elsewhere.

oh! so what would be the other reason that's causing it to stall? bad gear box?

it's 1996 SL320

 

[grober]

There are several other inputs to idle control other than engine revs. The system should also compensate for other inputs such as the increased load of air conditioning and should also compensate for simply putting the autobox into gear. Sounds as if its maybe not getting one of these inputs to increase the revs slightly to compensate. As Stats says its almost impossible to stall an automatic that's properly set up. Remember also if you're new to MB's that the throttle pedal is a bit stiff for the first few mms of travel. You will get used to it and just push thro the "dead band"

 

[stats007]

A diagnostic test should tell you - the idle speed control is a shared module with cruise control (N4/3).

 

[television]

We could do with more info from you on this

What is the idle speed when warm.
Is it the same both hot and cold
Its a 96 car, would that be after 10-96
Does it pull and drive OK

One thing for sure, it could be the MAF if it dies when idling, it is the hot film type. You could try unplugging it, as they sometime run fine without it to test.

Re as said above the Fault could show up on STAR, a lot more info can be had from a car after 06-96