Thanks for the suggestions. I thought I'd give you an update 
Can it be something to do with faulty glow-plugs? I've had the same situation 3 times during the last few days - that the car wouldn't start. The way I get it to start is ignoring the usual key sequence and just forcing the key quickly into Position III.
I mean, normally, I'd put the key in, turn a bit (click) turn again (click) and then engage the starter. Now I just put it in and force it around instantly till the engine begins to cought and eventually starts.
Very weird.
I guess I'll have to get a new solenoid to eliminate that as a cause.
Can it be something to do with faulty glow-plugs? I've had the same situation 3 times during the last few days - that the car wouldn't start. The way I get it to start is ignoring the usual key sequence and just forcing the key quickly into Position III.
I mean, normally, I'd put the key in, turn a bit (click) turn again (click) and then engage the starter. Now I just put it in and force it around instantly till the engine begins to cought and eventually starts.
Very weird.
I guess I'll have to get a new solenoid to eliminate that as a cause.