SLK intermittent start problem

[munchie]

Hi everyone, i have a small problem on my girlfriends SLK, its a 1997 230SLK.
Every once and a while the car seems to turn over for too short a time to actually start, ive tried putting jump leads on it but it makes no difference, if left for a while it will start again. When we took it to a garage the last time it happened they couldnt find a fault with the battery or altenator??? Any ideas?
Alan

 

[Benzman]

Check that the earth connection between battery and car bodywork is secure and tight.

 

[munchie]

its tight, it started fine when we got back from work and again this morning???

 

[television]

I think Crank shaft Sensor £47 from Bosch and dead easy to fit

 

[munchie]

Thanks thats gotta be worth a try, we'll get one for the MOT in June.