Originally Posted by FletchCossie

Crank Position Sensor iirc...

Had similier problem on my Vaux Astra. Tried 2 new sensors with same problem. Fitted an 97,000 mile one and it still works now

Edited to say: My Astra was receiving all voltages iirc, but it was not receiving the correct signal from the sensor, hence it didn't know when to spark!