320 (petrol) Stall at Junction

[Eazi]

So the car (2001 CLK 320 Covertible Automatic) is running fine 90% of the time.

But... a couple of times now, I have stopped at traffic lights or junctions and whilst stationary the refs still rock solid and stable at around 500rpm. Then, when I go to pull off, instead of the usual normal smooth pull away, the revs drop right away for upto a second or so.

A few times I have put my foot more firmly on the accelerator and the car pulls off like a boy racer at Santa Pod, but if I try not to induce this racing start, the car has stalled a couple of times.

The car starts traight back up and tends not to show the symptoms again for a while.

Help !!

 

[Bobby Dazzler]

My guess is the Crank Position Sensor (CPS)

 

[SpanishBattery]

I had the same problem. Sometimes wouldn't happen for weeks, then became more frequent and I'd have to wait for the engine to cool before it could be restarted. Engine warning light eventually just stayed on too.
Everyone said it would be the crankshaft sensor, and they were right.
Got one off eBay (raceparts) for 10.48. At that price it was worth a go, cheaper than diag, merc cps was 95.
Fitting was a doddle using a stubby driver with a 6mm socket on.
Could feel a difference straight away, and the warning light went off after the first short run, never to return.
It's worth a go.

 

[Eazi]

Hasn't done it since...
Its due for a aircon service / diag run soon anyway so think i'll leave it til then