Hi David, I agree with the general consensus here that it is probably an air-in-fuel problem or an electrical problem.
When it fails you need to do the procedure of priming the fuel filter to get air out and if that improves matters then you can start looking for air leaks.
I would also suggest that you check that the battery terminals are very clean and tight and check that the main earthing strap earthing the engine to the chassis is also clean and tight.
I had a very similar problem on my 2002 Export CRD where the Jeep would suddenly glide to a halt and as you stop the oil light comes on...don't panic about the oil light...... it is basically saying that the engine cut out.
In the fuse box under the "hood' as our USA friends call it....there are lots of relays.
One relay is marked as the ASD or Auto Shut Down relay. I had a loose connection going to this relay which would cause the engine to cut off if I went over a bump in the road. I found the bad connection and all works well now.
You could try pulling out the ASD relay while the engine is at idle and you should see the same symptoms....dies completely and oil light comes on! Try swapping this relay over with an identical one and clean the relay pins while you are about it.
Try and get some error codes. If you do not have access to a code reader then your model should work whereby you turn the ignition key ON/OFF rapidly 4 times without starting the engine. With the ignition left ON after the forth time the odometer cycles through error codes from oldest to newest. It takes a few attempts to get this method to work and often the last two digits are transposed so a "P1025" code may be true or could be a "P1052" error for example.
