crankshaft position sensor??

[trikstar]

my polo has been riddled with problems of late and so far i have replaced the following

starter motor
alternator
ignition switch
gearbox mount


the problm is that when i start the car, it doesnt turn over. i can leave it and come home from work and start it again and voila, it starts. it will start again if not left for too long but mainly the problems occurs if i leave it overnight.

The drive is not as smooth as it used to be so i am left wondering what it could be. the mechanic mentioned the dodgy fuel Tesco put out so he ran a diagnostic and the crankshaft position sensor came up as faulty..


has anyone changed theirs from having similar symptoms?

thanks