Our 2002 Fabia randomly refuses to start though the engine spins over suggestions so far coolant temp sensor, MAP sensor, throttle body temp sensor cleaning, crank sensor and new battery (battery light on sometimes). Any body got any experience of fixing this ?

Check the voltage on battery when stopped. It should read 12.5 -12.8v. If it starts it should be 13.7-14.7v. It could be a failing alternator or the exciter wire is broken so alternator not charging battery some of the time (thin wire going to alternator) which would explain battery light. If the battery is low it may be why the car doesnt start randomly as electronic systems are very susceptible to low voltage unlike the starter motor which will turn at lower speed even if voltage is low and cause a big voltage drop. Also check battery terminals are good and not corroded and also earth points.

Alasdair

Edited 6 hours ago6 hr by Alasdair1