The problem only appeared a couple of weeks ago, did it once or twice to me only.
Only ever on cold start, no problems after the engine had been running.
Turn to start, engine fires up perfectly but then instantly dies.
Second go and it would be fine (both of these are without using any throttle).
For the last week it's been fine. Then I went to use the car this afternoon and it didn't go on the second turn either so I grabbed my phone and perversely crossed my fingers;
So there you go, twice more on there, exactly the same.
The third time on the video I blipped the throttle on start and it held fine.
This evening Lisa tells me it died on her at the lights (this was only about a minute from the house). So that's bloody annoying.
Idle is absolutely fine, rock solid, smooth and at the right revs at all temps. Engine runs absolutely fine in all other ways, no misfires, not down on power etc. etc.
This intermittent fault appeared before I changed the coolant last weekend.
Of course it's dark and drokking cold out there, so trying to fault find now is a no-go now and during the week I also get home from work too late every night
Currently this is the only car we have on the road and next weekend is the soonest I'll have time to have any proper play around on it 
So, besides main relay, ignition switch, what are peoples ideas?
