UK Car Repair Questions? Ask a Mechanic for Answers ASAP
I am sorry that you have not been helped yet. I just came online and saw your question
Is the check engine/service engine soon light on, and if so, what are the fault code numbers?
without knowing this, my first suggestion would be to check the injectors for leaking down and causing loss of fuel pressure.
any smoking on start up when it does eventually start, or any fuel in the oil
Without testing I cant be sure, but it does sound like the injectors or leaking down