Inspect the fuel pump relay mate as that is the exact same problems I was having.

The car would start 1st time every time and tick over for a few seconds and then die. However, if you started it and rev. it to 2.5k + for about 20-30 seconds and then released the throttle it would idle fine (would sound a bit wrough at first when the accelerator was being held).

The fuel pump relay has a switch which has two different power supplies. It has a power supply when you first start the car and once started it switches over to a power supply which reads the impulses from the coil. This way if the engine stalls or fails the fuel supply will be cut off. (not very well described, sorry)

Basically, my fuel pump relay was switching over to the second supply and thinking the engine wasn't running so was just cutting the fuel supply.

Good luck mate