artificer

Mercedes I have not worked on in my career, so ask for assistance here, please.

My current wheels fit a 1981 R107 Euro 500SL without too much emissions paraphernalia fitted. [no EGR or air pump or catalytic converter].

This car runs wonderfully well, not missing a beat, as a big cruiser with a genuine 188000km.
I replaced the valve stem oil seals the week before last & the dreaded white smokescreen on cold take off has gone west, hopefully for ever.

Now after the car warms up, while idling @ traffic lights or just parked it will idle @ about 650-750RPM for 1 minute or 2 then start to 'hunt' & stall.
Any attempt @ restart, it only wants to idle about 500RPM & immediately stops/stalls.

Only way to get going again is with foot on throttle a bit. Once auto is engaged & rolling let foot off & will idle @ 6509-750RPM again.
Very annoying....so any ideas appreciated please....


1. What is the control accessed thru the air cleaner with an allen key for?

2. Also the white coloured screw just in front of the air cleaner for?

3. Any particular sequence used?


4. Where is the PCV valve on these cars?
Charcoal canister has TANK + PCV & VACUUM ports currently looped....

Also a thermostatic switch valve colour red under air cleaner is also looped....
5. Where should each side of this colour red switch be piped?

6. What is the valve under the coolant overflow tank with an inlet & outlet? [vacuum?] One side currently goes to the LH [1-4] rocker cover via the rubber connector to the air cleaner....the other port on the valve is plugged.
7. Where do these hook up to?

A simple mud map of a basic vacuum layout on this car would be appreciated.