Idling Problem C230K

[bigasotonuk]

Hi,
Hope some one has some ideas to this problem as this is really annoying me.
The car is a P reg C230K Sport manual gearbox i,ve had the car 4+ years now and i,ve done over 90,000 miles in it.
It has developed a problem when idling, when coming to a stop throttle off clutch down the tick over will drop alarmingly low and almost stall (occasionally it will stall) but 90% of the time after a short period it picks back up and settles at the correct idle speed.
I had a problem similar to this but on my old 2.0 Granada and it was a sticking
electric valve in the injection system.
Any ideas guys? all help much appreciated :-?

 

[C220GJS]

Possibly a gummed up idle control/throttle butterfly valve ,clean with carb cleaner or similar solvent. Also make sure your throttle linkages are well lubricated and returning properly and that there are no broken return springs.
Geo.

 

[bigasotonuk]

Erractic Idle

Hi,
I,ve looked for something like this, but i don,t think the systems got one as such. On my E12 BMW M535i and my E28 BMW M535i, I had a air flow meter (AFM) with a flap, which i would clean to improve the idle. But wot they call an AFM (also called a MAF sensor) on the merc has no flap just a air flow sensor in the pipe. This has been replaced and yes the throttle linkage was a a bit sticky it now free an loose snaps clean shut now. This has improved it no-end stalls out still but a lot less.
Thanks for post though, anymore ideas??:-(
Andy.

 

[C220GJS]

no.86 on this diagram is your idle speed actuator ;http://www.detali.ru/cat/oem_mb2.as...GM=717.460&CT=M&cat=19K&SID=07&SGR=040&SGN=01 . It is a different layout to accomodate the compressor and intercooler but otherwise it has the same parts in the system.
Geo.
Edit:- The vertical trunking is for the compressor engines ,yours could be either of the 2-diagrams but anyway you have an idle control valve.

 

[bigasotonuk]

idle speed problem

Hi,
Thanks for the link will check it out at home as the firms PC won,t allow the site.
Andy.