A Volvo 940 GL 1993 is not starting. It is getting fuel, but the spark comes when the ignition key is released and going back to the off position. Any ideas?

 

With your noid light - do you have a pulse at the injector when the engine is spinning over? What is the condition of the wiring going to the crank sensor? What's the resistance in the sensor?

If your crank position sensor is not sending the correct signal - the ign coil may only fire when the key is turned on or off.

 

I had the same problem. Turned out to be a weak magnet on the crankshaft position sensor which is easy access on the transmission bell housing.