I have a TE Exec, Auto, my friend is using it at the moment and had been having issues with it taking ages to Start,

Took it to the Mechanic who looked at it and said it sount like it was Fuel pump.

So replaced it and Fuel Filter and now having the same issue still,

Now some times it will start after a while other times it won't, But if you leave it for a few minutes it starts again.

Any help would be greatly appreciated,

Could be losing fuel pressure due to a leak or faulty pressure regulator. Good way to test this is crank it once for breif moment then wait a few seconds with the ignition on and try cranking again (should fire right away). The brief crank will start the fuel pump and pressurise the system, next try and it should work.

If you have it running, then stop it will it restart easily right away?

Sounds like the factory immobiliser, it should have an engine code now saved in the system.

You can manually read these codes, however you would have to do a search as there is a thread with how to read it (you ground a pin on the plug under the dash) and what codes mean what.

Or if you have a repair manual they cover it there too.