Idle speed control w124 300D

[petermerle]

My 87 300D idle speed control stops working when under the hood temps get high. Idle then runs up to around 1700 rpm . The voltage going to the idle servo on the inj pump also then increases to 12V from the normal 2.5 - 3.5 V. Anyone got any idea what the cause of this is?
Peter

 

[bolide]

87 300D with an idle servo?

AFAIK the 93-on 606-engined cars have digitally stabilised idling but the early cars don't. AFAIK they have a cold-start enrichment system only

is this a UK car? Have you checked it against the Russian website to find out what kit it has as standard?

Nick Froome
www.w124.co.uk

 

[petermerle]

Mine definitely has idle speed control - - if you want to check its vin details it is ADB1241306A285123. For the russian site to recognise the VIn you have to replace the ADB ( Made in South Africa ) with WDB .
Peter

 

[bolide]

http://www.detali.ru/cat/oem_mb2.as...GM=717.430&CT=M&cat=503&SID=07&SGR=045&SGN=01

Nick Froome
www.w124.co.uk

 

[Dieselman]

Check the OVP for dry joints first.

 

[mattc]

Check the OVP for dry joints first.

When you say "dry joints" do you mean inside the relay itself or at the pins/sockets? If only external what should they be sprayed with to clean?

 

[Dieselman]

I mean inside really, but no harm in using contact cleaner on the connections.

 

[mattc]

I mean inside really, but no harm in using contact cleaner on the connections.

So how do you check a relay internally then?

 

[petermerle]

Where do you find the OVP and the Controller ? Is it behind the battery ? Mine is RHD
Peter

 

[SilverSaloon]

Where do you find the OVP and the Controller ? Is it behind the battery ? Mine is RHD
Peter

remove the plastic trim cover just behind the battery. It lives under there.

You'll have to put the bonnet to 90deg to access it properly.

also, more info here:

http://www.mbclub.co.uk/forums/showthread.php?t=60927&highlight=ovp+relay